_General characters._--Pelage with lanceolate aristiforms limited
to an area on the dorsal surface between the shoulders and the
hips; length of tail less than 90 per cent of length of head and
body; skull with conspicuous ridges; extension of supraorbital
ridges always evident on parietals; infraorbital foramen usually
with separate groove for transmission of nerve; palate usually
extended posteriorly as far as third molars; incisors opisthodont;
molariform teeth with a small main fold, never extended
transversely to opposite wall in occlusal surface of tooth; usually
one counterfold anterior to main fold in upper molariform teeth and
posterior to main fold in lower molariform teeth; premolars usually
smaller than first molars, first molars smaller than second molars
but second molars larger than third molars.
=Proechimys goeldii= Thomas
_General characters._--Size large; tail short; aristiforms narrow
and soft, usually concealed in pelage by setiforms; general color
of upper parts some tint of orange, gradually becoming lighter on
sides with no conspicuous, dark longitudinal band on back; feet
dark; ventral surface of body and inner side of legs white but
sometimes with some buff locally; skull broad and strongly built
but not conspicuously ridged; zygomatic expanse great and rostrum
not elongate; incisive foramen narrow; bullae large and inflated;
upper molariform teeth with three to four counterfolds, M3
ordinarily with four; lower premolars with four, and molars with
three, counterfolds.
=Proechimys goeldii steerei= Goldman
_Proechimys steerei_ Goldman, Proc. Biol. Soc. Washington, 24:238,
28 November 1911 (original description); Goldman, 1912, Proc. Biol.
Soc. Washington, 25:186; Tate, 1935, Bull. Amer. Mus. Nat. Hist.,
68(5):400; Ellerman, 1940, The families and genera of living
rodents, Brit. Mus. (Nat. Hist.), 1:119; Osgood, 1944, Zool. Ser.
Field Mus. Nat. Hist., 29(13):204.
_Type locality._--Hyutanaham, Upper Purus, _Lábrea_, Amazonas,
Brazil. _Type:_ United States National Museum, no. 105535, adult
male; collected in 1901 by Prof. J. B. Steere.
_Range._--Known only from the type locality and Porto Velho.
_Diagnosis._--Upper parts Mars Orange on back, grading to
Ochraceous-Tawny on sides; zygomatic breadth narrow; nasals short;
incisive foramen narrow and short; vomerine sheath complete and
thick; upper molars usually with four counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Grayish basally,
gradually blackening toward tip; total length, 16 to 19 mm;
maximum width, 0.5 mm. _Setiforms on middorsal region_: Grayish on
basal third, gradually blackening toward tip but interrupted by a
Mars Orange, subapical zone 1.5 mm long; total length, 16 to 19
mm; maximum width, 0.06 mm. _Setiforms on outer thighs_: Whitish
basally, gradually blackening toward tip but interrupted by Orange
Rufous or Ochraceous-Tawny, subapical zone; total length, 14 to 16
mm; maximum width, 0.05 mm.
[Illustration: FIGS. 25, 27. _Proechimys goeldii steerei_, sex ?,
"Hyutanaham," USNM no. 105537. × 1.]
[Illustration: FIGS. 26, 28. _Proechimys goeldii goeldii_, female, AMNH
no. 37488. × 1.]
[Illustration: FIGS. 29, 30. _Proechimys goeldii steerei_, sex ?, USNM
no. 105537, "Hyutanaham." × 1.]
[Illustration: FIGS. 31, 32. _Proechimys goeldii goeldii_, female, AMNH
no. 37488, Fazenda Paraiso. × 1.]
_Skull._--Large and strong; rostrum rather pointed posteriorly;
supraorbital ridges not much expanded and extending across
anterior half of parietals; infraorbital foramen without groove
for transmission of nerve, or groove obsolete; zygomatic arches
slender; postorbital process of zygoma involving mostly squamosal;
incisive foramen short and narrow (4.5 × 2.5 mm) with margins
almost parallel or tapering gradually caudad and extending toward
palate as ridges; posterior margin of incisive foramen
approximately 2.5 mm anterior to premolars; vomerine sheath
complete, with both elements well-developed; mesopterygoid fossa
never extending anterior to middle of M3; bullae large, well
inflated and with shallow grooves.
_Teeth._--Upper molariform teeth: P4 with three counterfolds;
upper molars with four counterfolds each or, less commonly, three.
Lower premolars with four counterfolds; lower molars with three
each.
_Comparisons._--From _P. g. goeldii_, _steerei_ differs in: Back
and sides with more reddish; narrower interorbitally and across
zygomata; palatilar length less and nasals shorter; maxillary part
of vomerine sheath thicker; usually four instead of three
counterfolds in M3.
_Remarks._--This subspecies is clearly related to _P. goeldii_. One
skull from Porto Velho, Rio Madeira, _Guaporé_, Brazil (CNHM no. 21558)
may belong to an unnamed subspecies but is provisionally included here.
In the field notes of Professor Joseph Beal Steere, an entry for no. 72
reads: "Big white bellied wood rats x two young found in nest of grass
on the ground with the two young--_much darker_ young female." No. 77 in
his field notes corresponds to the type specimen.
_Specimens examined._--Total number, 4, from Brazil, as follows:
Amazonas. _Lábrea_, Hyutanaham, 3 (USNM); Territ. Guaporé, Porto
Velho, 1 (CNHM).
=Proechimys goeldii goeldii= Thomas
_Proechimys goeldii_ Thomas, June 1905, Ann. Mag. Nat. Hist., 15
(ser. 7):587, (orig. descr.); Thomas, 1912, Ann. Mag. Nat. Hist., 9
(ser. 8):89; Thomas, 1920, Ann. Mag. Nat. Hist., 6 (ser. 9):277,
Tate, 1935, Bull. Amer. Mus. Nat. Hist., 68(5):400; Osgood, 1944,
Zool. Ser. Field Mus. Nat. Hist., 29(13):199.
_Proechimys cayennensis goeldii_, Ellerman, 1940, The families and
genera of living rodents, Brit. Mus. (Nat. Hist.), 1:121.
_Type locality._--Santarem, _Santarem_, Pará, Brazil. Type: British
Museum (Nat. Hist.), no. 5.1.25.6, adult female; presented by Dr.
E. A. Goeldi.
_Range._--Margins of the Amazon, between Jamundá and Tapajoz
rivers.
_Diagnosis._--Upper parts Ochraceous-Tawny; wide across zygomata;
nasals of moderate length; incisive foramen long and narrow;
vomerine sheath complete but maxillary part slender; first and
second upper molars with four counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally and
gradually blackening toward tip which is extended as long, thin
filament; total length, 22 to 24 mm; maximum width, 0.5 mm.
_Setiforms on middorsal region_: Gray basally, gradually
blackening toward tip but interrupted by Ochraceous-Tawny,
subapical zone 3.3 mm long; total length, 19 to 21 mm; maximum
width, 0.06 mm. _Setiforms on outer thighs_: Whitish basally,
gradually blackening toward tip but interrupted by
Ochraceous-Tawny, subapical zone 3 mm long; total length 14 to 16
mm; maximum width, 0.04 mm.
_Skull._--Large and strong; nasals pointed posteriorly;
supraorbital ridges moderately developed and extended caudad
across anterior third of parietals; zygomatic arches strong;
postorbital process of zygoma involving mostly squamosal; incisive
foramen elongate and narrow (5 to 6.5 x 2.3 mm) with margins more
or less parallel and raised to form ridges which extend posteriorly
to within 3 mm of plane of premolars; vomerine sheath complete,
with maxillary part thin and extended caudad as medial crest;
mesopterygoid fossa extending forward as far as posterior faces
of second molars or slightly short thereof; bullae large and
inflated.
_Teeth._--Molariform teeth large, P4-M3 averaging more than 9 mm
in length. Upper molariform teeth: P4 and M3 with three
counterfolds; M1 and M2 with four counterfolds each. In lower
teeth, p4 with four counterfolds and each molar with three
counterfolds.
_Comparisons._--Differences from _P. g. steerei_ are given in the
account of that subspecies.
_Remarks._--Specimens from the type locality were not available.
Specimens from Fazenda Paraiso, Faro, were relied upon as representative
of the subspecies. These agree with the type according to Thomas
(1912:89). However, the skin of the type was changed in color by
preservative (Thomas, 1905:587) and the best skin he saw was from Faro
(1912:89).
Thomas (1920:277) applied the name _goeldii_ also to specimens from
Manacaparú, a place a short distance above Manaus on the Solimões
(Amazon) River and from Acajutuba, near Manaus, on the Negro River. In
referring to these specimens (2 from Manacaparú and 2 from Acajutuba)
Thomas (_loc. cit._) said "Five molar laminae are frequently, if not
invariably, present among these specimens." He did not, however, mention
whether or not the number of laminae was constant in both M2 and M3. One
specimen from Acajutuba, in the collection of Museu Nacional (MN no.
1973 [M]), actually has five laminae in M3, but the specimens in the
American Museum from Faro agree absolutely with Thomas' original
description of _goeldii_.
Osgood (1944:199) doubted that _goeldii_ was a valid species. Evidence
that Osgood's doubt was unjustified is furnished by the fact that Thomas
(1912:89) pointed out that his specimen from Faro agrees with the type.
Likewise, my two specimens from Faro agree with the type insofar as it
has been described. Thomas (1912:89) mentioned two additional skulls
from the type locality which, he stated, agree with the type which was
received from the Museu Goeldi, Pará.
_Specimens examined._--Total number, 4, from Brazil as follows:
Pará, _Faro_, Faro, Fazenda Paraiso, 2 (AMNH); Amazonas, _Manaus_,
Manaus, 1 skull (AMNH); Amazonas, _Manaus_, Acajutuba, 1 (MN).
_Additional records._--Total number, 7 (British Museum), from
Brazil, as follows: Pará, _Santarem_, Santarem (Thomas, 1912:89;
1920:277), 3; Amazonas, _Manaus_, Acajutuba (Thomas, 1920:277), 2;
_Manacaparú_, Manacaparú (Thomas, 1920:277), 2.
=Proechimys semispinosus= (Tomes)
[Illustration: FIGS. 33, 36. _Proechimys semispinosus liminalis_,
female, MN no. 6253, Rio Quichito. Type. × 1.]
[Illustration: FIGS. 34, 37. _Proechimys semispinosus amphichoricus_,
male, AMNH no. 77020, Mount Duida. Type. × 1.]
[Illustration: FIGS. 35, 38. _Proechimys semispinosus kermiti_, female,
AMNH no. 37124, Lower Rio Solimões. Type. × 1.2 (from photograph).]
_General characters._--Size large; tail short and hairy;
aristiforms wide and stiff, especially well-developed on back;
general color on upper parts some shade of ochraceous, usually much
darker on back and forming a conspicuous dorsal band; feet dark;
ventral surfaces and inner sides of legs white; skull elongate and
strong with ridges well developed; incisive foramen long and
narrow; bullae large; usually four counterfolds in M3 and M2;
usually three but sometimes four counterfolds in M1 and even P4;
lower premolar with four and lower molars with three counterfolds.
[Illustration: FIGS. 39, 40. _Proechimys semispinosus liminalis_,
female, MN no. 6253, Rio Quichito. Type. × 1.]
[Illustration: FIGS. 41, 42. _Proechimys semispinosus amphichoricus_,
male, AMNH no. 77020, Mount Duida. Type. × 1.]
[Illustration: FIGS. 43, 44. _Proechimys semispinosus kermiti_, female,
AMNH no. 37124, Lower Rio Solimões. Type. × 1.2 (from photograph).]
=Proechimys semispinosus liminalis= subspecies nova
_Type locality._--Rio Quichito, affluent from the south of the
Javarí River, near _Benjamin Constant_, Benjamin Constant,
Amazonas, Brazil. _Type_: Museu Nacional, no. 6253, adult female,
collected in August, 1942, by E. Parko.
_Range._--Known only from the type locality.
_Diagnosis._--Color uniformly dark, setiforms marked with
Ochraceous-Tawny; skull wide across zygomata; nasals short;
prepalatilar part of skull long; incisive foramen long and narrow;
vomerine sheath incomplete or complete; M2 and M3 almost always
with four counterfolds; M1 more rarely with four counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip which is generally extended as a
filament; total length, 21 to 23 mm; maximum width, 0.9 to 1 mm.
_Setiforms on middorsal region_: Gray basally, gradually
blackening toward tip but interrupted by Ochraceous-Tawny,
subapical zone 3 mm long; total length, 22 to 24 mm; maximum
width, 0.06 mm. _Setiforms on outer thighs_: Whitish basally,
gradually blackening toward tip but interrupted by Ochraceous-Buff,
subapical zone 2.5 mm long; total length, 13 to 15 mm; maximum
width, 0.08 mm; some with gray base, blackening gradually toward
tip, without any subapical zone; some with Light Ochraceous-Tawny,
subapical zone.
_Skull._--Large and strongly built throughout; supraorbital ridges
expanded and thick, extending, in old specimens, across parietals
to anterior angles of interparietals; interparietal ridges always
conspicuous; rostrum elongated; nasals blunt posteriorly;
zygomatic arches strong; infraorbital foramen with
weakly-developed groove for transmission of nerve; postorbital
process of zygoma involving mostly squamosal; incisive foramen
averaging 6 x 2.7 mm, widest in middle part and posteriorly
constricted, with raised margins which do not extend across
maxillae as ridges; posterior margin of incisive foramen
approximately 1.5 mm anterior to plane of premolars; vomerine
sheath incomplete or, sometimes, complete but always with
maxillary part slender; mesopterygoid fossa not extending forward
past centers of third molars; bullae moderately developed.
_Teeth._--Upper molariform teeth: P4 always with three
counterfolds; M1 with three counterfolds in 9 of 10 specimens and
four counterfolds in remainder; M2 with four counterfolds in 7
specimens, three counterfolds in remainder; M3 with four
counterfolds in 6 specimens, three counterfolds in remainder.
Lower premolar always with four, and molars with three,
counterfolds.
_Comparisons._--From _P. s. semispinosus_, _liminalis_ differs in:
darker color; wider aristiforms; greater percentage of upper
molars with four counterfolds. From _P. s. amphichoricus_,
_liminalis_ differs in: lighter upper parts of almost uniform
color instead of with conspicuous, blackish, middorsal,
longitudinal band; more strongly built skull; longer incisive
foramen; vomerine sheath usually incomplete instead of always
complete.
_Specimens examined._--Total number, 10 (MN) from the type
locality.
=Proechimys semispinosus amphichoricus= subspecies nova
_Type locality._--Mount Duida, Esmeralda, _Amazonas_, Venezuela;
altitude 325 m. _Type_: American Museum of Natural History, no.
77020, adult male; collected 16 October 1920 by Olalla Bros.
_Range._--Headwaters of Negro and Orinoco rivers, along boundary
of Brazil and Venezuela.
_Diagnosis._--Color dark, blackish on middorsal area; subapical
zone of setiforms on back Buckthorn Brown, but many with distal
parts black; skull broad across zygomata; nasals long;
prepalatilar area of skull long; incisive foramen long and narrow;
vomerine sheath complete; upper molars usually with four
counterfolds but P4 usually with only three.
_Pelage._--_Aristiforms on middorsal region_: Grayish basally,
gradually blackening toward tip; total length, 18 to 20 mm;
maximum width, 0.8 to 1.0 mm. _Setiforms on middorsal region_:
Gray basally, gradually blackening toward tip but interrupted by a
light (16 i), Buckthorn Brown, subapical zone 2 mm long; total
length, 18 to 22 mm; maximum width, 0.03 mm. Most of them,
however, whitish basally, gradually blackening toward tip without
any distinctively-colored, subapical zone; total length, 24 to 26
mm; maximum width, 0.5 mm. _Setiforms on outer thighs_: Whitish
basally, gradually blackening toward tip but interrupted by an
Ochraceous-Buff, subapical zone 3.5 mm long; black tip short; total
length, 17 to 19 mm; maximum width, 0.05 mm.
_Skull._--Large and slender; rostrum elongate; nasals bluntly pointed
posteriorly; supraorbital ridges thick (but not expanded) and extending
across parietals but almost obsolete in middle part of parietals;
infraorbital foramen with weakly-developed groove for transmission of
nerve; postorbital process of zygoma involving mostly squamosal;
incisive foramen 5.5 x 2.8 mm wide in anterior third, with margins
constricted posteriorly and extending as ridges approximately 2 mm
beyond posterior margin of incisive foramen; posterior margin of
incisive foramen approximately 2.5 mm anterior to premolars; vomerine
sheath complete with maxillary part weak and premaxillary part extending
posteriorly beyond middle of incisive foramen; mesopterygoid fossa
extending forward as far as middle of M3; bullae well inflated and
elongated.
_Teeth._--P4 with four counterfolds in one of five specimens and with
three in remainder; M1 with four counterfolds in three of five specimens
and with three in remainder; M2 with three counterfolds in one specimen
and with four in all four remaining specimens; M3 always with four
counterfolds. Lower premolars with four counterfolds and lower molars
with only three.
_Comparisons._--The subspecies is easily distinguishable from _P. s.
angularis_ by: larger number of black setiforms on back, forming an
almost black longitudinal band; more elongate skull; larger and longer
bulla; longer incisive foramen which is more constricted posteriorly.
_Specimens examined._--Total number, 6 (AMNH), as follows:
Venezuela, territ. _Amazonas_, Esmeralda, Mt. Duida, altitude 325
m., 4; Venezuela, territ. _Amazonas_, Rio Cassiquiare, Quemapuré,
1; Brazil, Amazonas, _São Gabriel_, Rio Uaupés or Caiari, Tatú, 1.
=Proechimys semispinosus kermiti= Allen
_Proechimys kermiti_ Allen, 30 December 1915, Bull. Amer. Mus. Nat.
Hist., 34(22):629 (orig. descr.); Allen, 1916, Bull. Amer. Mus.
Nat. Hist., 35(30):569; Tate, 1935, Bull. Amer. Mus. Nat. Hist.,
68(5):400; Ellerman, 1940, The families and genera of living
rodents, Brit. Mus. (Nat. Hist.), 1:119.
_Type locality._--Lower Rio Solimões (up the Solimões 50 to 60
miles on the north bank of the river), _Manacaparú_, Amazonas,
Brazil. _Type_: American Museum of Natural History, no. 37124,
adult female; collected 20 April, 1914, by Leo E. Miller (Roosevelt
Brazilian Expedition).
_Range._--Known only from type locality.
_Diagnosis._--Upper parts Tawny, with darker longitudinal band on
back, gradually becoming Ochraceous-Buff on sides; zygomata widely
spread; nasals long; incisive foramen long; vomerine sheath
incomplete; only M3 with four counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Grayish basally,
gradually blackening toward tip; total length, 18 to 20 mm;
maximum width, 0.8 mm. _Setiforms on middorsal region_: Grayish
basally, gradually blackening toward tip but interrupted by Tawny,
subapical zone 2 mm long; total length, 18 to 20 mm; maximum
width, 0.06 mm; some blackened toward tip without subapical zone.
_Setiforms on outer thighs_: Whitish basally, gradually blackening
toward tip but interrupted by Ochraceous-Buff, subapical zone
2.5 mm long; total length, 18 to 20 mm; maximum width, 0.05 mm.
_Skull._--Large, elongate, and strongly built; rostrum not
conspicuously elongated; nasals bluntly pointed posteriorly;
supraorbital ridges wide and extending posteriorly across parietals
almost to level of interparietal; infraorbital foramen with
moderate development of groove for transmission of nerve; zygomatic
arches slender; postorbital process of zygoma involving mostly
squamosal; incisive foramen 6.5 mm long and 2.7 mm wide, wider in
anterior third and gradually constricted posteriorly, with margins
extended toward palate as ridges; vomerine sheath incomplete,
maxillary part threadlike; mesopterygoid fossa extending forward as
far as anterior third of m3; bullae large and well inflated.
_Teeth._--P4 with three counterfolds; M3 with four counterfolds;
M1 and M2 with three counterfolds. Lower premolars with four
counterfolds; lower molars with three counterfolds.
_Comparisons._--From _P. s. amphichoricus_, _kermiti_ differs in:
upper parts Tawny instead of Buckthorn Brown; incisive foramen
longer and wider; vomerine sheath incomplete; only M3 instead of
usually all molars, with four counterfolds. From _P. s.
liminalis_, _kermiti_ differs in: upper parts Tawny instead of
Ochraceous-Tawny; aristiforms narrower; M3 only, instead of
usually M2 and M3, with four counterfolds.
_Specimens examined._--Only the type.
=Proechimys longicaudatus= (Rengger)
_General characters._--Size medium to large; tail short;
aristiforms long and narrow; general color on upper parts
Ochraceous-Buff to Ochraceous-Orange, finely and uniformly lined
with blackish and not forming evident dark band on back; feet
dorsally white or gray; underparts of body and inner sides of legs
white; skull elongate and slender with moderate ridges; incisive
foramen of medium size; vomerine sheath complete or incomplete;
bullae large and elongate; upper molariform teeth with three
counterfolds; lower molariform teeth with three counterfolds but
commonly one or two molars have only two although premolar may have
four.
_Remarks._--The identity of "_Echimys longicaudatus_ Rengger" can be
ascertained only after samples have been collected in the area indicated
by Rengger: "unter dem ein und zwansigsten Breitengrade" in Paraguay. Of
the samples available to me, those from Urucum, in western Brazil, are
geographically nearest the type locality. North of Urucum, both in
Brazil and Bolivia, two species of _Proechimys_ live together and one of
them is the same species as that at Urucum. Of the two species found to
the northward in Brazil and Bolivia, the one that ranges farther south
probably will occur at the locality indicated by Rengger. Provisionally,
therefore, the name _longicaudatus_ is allocated to the Urucum sample
(see Osgood, 1944:198). In fact, the lack of a type specimen and the
general nature of Rengger's description make "_Echimys longicaudatus_" a
_nomen vanum_. If two species are found living together in the region of
northern Paraguay indicated by Rengger it probably will be impossible to
be sure to which one his vague description applies.
The form from Urucum, to which the name _Proechimys longicaudatus_ is
here applied, is undoubtedly closely related to _Proechimys leucomystax_
Ribeiro, from Utiarití, on the Rio Papagaio and also to _P. roberti_ and
_P. boimensis_, all from Brazil. _P. longicaudatus_ is used as the name
of the species because it is the oldest of the four names.
[Illustration: FIGS. 45, 48. _Proechimys longicaudatus boimensis_, male,
MCZ no. 30881, Boim. × 1.]
[Illustration: FIGS. 46, 49. _Proechimys longicaudatus longicaudatus_,
male, AMNH no. 37085, Urucum. × 1.]
[Illustration: FIGS. 47, 50. _Proechimys longicaudatus leucomystax_,
male, AMNH no. 37509, Tapirapoã. × 1.]
[Illustration: FIGS. 51, 52. _Proechimys longicaudatus roberti_, male,
MN no. 6233, Pouso Alto, Goiaz. × 1.]
[Illustration: FIGS. 53, 54. _Proechimys longicaudatus boimensis_, male,
MCZ no. 30881, Boim. × 1.]
[Illustration: FIGS. 55, 56. _Proechimys longicaudatus longicaudatus_,
male, AMNH no. 37085, Urucum. × 1.]
[Illustration: FIGS. 57, 58. _Proechimys longicaudatus leucomystax_,
male, AMNH no. 37509, Tapirapoã. × 1.]
[Illustration: FIGS. 59, 60. _Proechimys longicaudatus roberti_, male,
MN no. 6233, Pouso Alto, Goiaz. × 1.]
=Proechimys longicaudatus brevicauda= (Günther)
_Echimys brevicauda_ Günther, 1 April 1877, Proc. Zool. Soc. London
for 1876, (49):748, fig. 9.
_Proechimys brevicauda_ Ihering, 1904, Rev. Mus. Paulista, S.
Paulo, 6:422; Osgood, 1914, Zool. Ser. Field Mus. Nat. Hist.,
10(12):168; Thomas, 1924, Ann. Mag. Nat. Hist., 13 (ser. 9):534;
Thomas, 1927, Ann. Mag. Nat. Hist., 19 (ser. 9):553; Thomas, 1927,
Ann. Mag. Nat. Hist., 20 (ser. 9):604; Thomas, 1928, Ann. Mag.
Nat. Hist., 2 (ser. 10):262; Thomas, 1928, Ann. Mag. Nat. Hist., 2
(ser. 10):292; Tate, 1935, Bull. Amer. Mus. Nat. Hist., 68
(5):399; Osgood, 1944, Zool. Ser. Field Mus. Nat. Hist., 29
(13):201.
_Proechimys cayennensis brevicauda_ Ellerman, 1940, The families
and genera of living rodents, Brit. Mus. (Nat. Hist.), 1:120.
_Type locality._--Chamicuros, Rio Huallaga, Peru. _Type_: British
Museum (Nat. Hist.), no. 69.3.31.7,[F]; _Lectoparatype_: British
Museum (Nat. Hist.), no. 66.1.29.8, from Upper Amazons (E.
Barttet), selected by Thomas (1900:301).
_Range._--Region of the headwaters and upper courses of the Juruá
and Ucaiali rivers, eastern Peru and northwestern Brazil.
_Diagnosis._--Upper parts Tawny and blackish without marked
longitudinal band on back; underparts buffy or white; aristiforms
narrow; skull slender; incisive foramen wide; vomerine sheath
complete; molariform teeth with three counterfolds, except p4 with
four and m3 with only two.
_Pelage._--_Aristiforms on middorsal region_: Blackish basally,
gradually blackening toward tip which is extended as a long
filament; total length, 18 to 20 mm; maximum width, 0.65 mm.
_Setiforms on middorsal region_: Gray basally, gradually
blackening toward tip but interrupted by Tawny, subapical zone 1.2
mm long; total length, 19 to 21 mm; maximum width, 0.1 mm.
_Setiforms on outer thighs_: Whitish basally, gradually blackening
toward tip but interrupted by Ochraceous-Tawny, subapical zone 3
mm long.
_Skull._--Slender but not elongated; nasals tapering posteriorly;
interparietals wide; supraorbital ridges not much extended and
faintly shown across parietals; jugals dorso-ventrally "wide" (3.5
mm); postorbital process of zygoma weakly developed; incisive
foramen 5.5 x 3 mm, oval, with posterior borders raised to form
ridges which extend toward premolars; vomerine sheath complete,
with maxillary part laterally compressed and extended toward
palate as ridge; mesopterygoid fossa extending forward as far as
third molars; bullae large and well inflated.
_Teeth._--Molariform teeth with three counterfolds, except p4
which has four and m3 which has only two counterfolds.
_Comparisons._--From _P. l. longicaudatus_, _brevicauda_ differs
in: upper parts Tawny instead of Ochraceous-Buff; lower premolar
with four instead of three counterfolds; m3 only, instead of both
m1 and m3, with two counterfolds. From _P. l. boimensis_,
_brevicauda_ differs in: upper parts Tawny instead of
Ochraceous-Orange; aristiforms wider; m3 with two instead of three
counterfolds.
_Specimens examined._--Total number, 3 (DZ), from Brazil, Amazonas,
_João Pessoa_, Rio Juruá.
=Proechimys longicaudatus boimensis= J. A. Allen
_Proechimys boimensis_ Allen, 24 July, 1916, Bull. Amer. Mus. Nat.
Hist., 35(27):523; Tate, 1935, Bull. Amer. Mus. Nat. Hist.,
68(5):400; Ellerman, 1940, The families and genera of living
rodents, Brit. Mus. (Nat. Hist.), 1:119.
_Proechimys cayennensis_ Osgood, 1944, Zool. Ser. Field Mus. Nat.
Hist., 29(13):199.
_Type locality._--Boim, Rio Tapajoz, Santarem, Pará, Brazil.
_Type_: American Museum of Natural History, no. 37486, adult male;
"October 10, 1911 (ex Museu Goeldi)."
_Range._--Along lower course of Tapajoz River.
_Diagnosis._--Upper parts Ochraceous-Orange; incisive foramen
posteriorly constricted; mesopterygoid fossa sharply pointed
anteriorly; p4 with four counterfolds, remaining molariform teeth
with three counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip which is extended as a long
filament; total length, 16 to 18 mm; maximum width, 0.5 mm.
_Setiforms on middorsal region_: Gray basally, gradually
blackening toward tip, but interrupted by short (1.5 mm),
Ochraceous-Orange, subapical zone; total length 18 to 20 mm;
maximum width 0.09 mm. _Setiforms on outer thighs_: White basally,
gradually blackening toward tip but interrupted by
Ochraceous-Orange, or Ochraceous-Buff, subapical zone 3.5 mm long;
total length 15 to 17 mm; maximum width, 0.06 mm.
_Skull._--Elongate and slender; rostrum slender and long; nasals
evenly pointed posteriorly; supraorbital ridges weak and barely
reaching anteriormost part of parietals; zygomatic arches slender;
infraorbital foramen with groove for nerve-transmission obsolete;
postorbital process of zygoma weak and involving mostly squamosal;
incisive foramen 5 mm long and 2.5 to 3 mm wide, oval, with
margins not much extended caudad as ridges; posterior margin of
incisive foramen approximately 2 mm anterior to premolars;
vomerine sheath complete with maxillary part slender;
mesopterygoid fossa sharply pointed anteriorly and extending
forward as far as anterior part of third molar; bullae of medium
size, smooth and more or less triangular in contour.
_Teeth._--Crown length of upper molariform teeth 7 to 7.5 mm; all
upper molariform teeth with three counterfolds; lower premolar
with four counterfolds; lower molars with three counterfolds each.
_Comparisons._--From three of the other four subspecies found in
Brazil, _boimensis_ differs in having four, instead of three,
counterfolds in the lower premolars. Differences from _P. l.
brevicauda_ are indicated in the account of that subspecies.
_Remarks._--The material available from Boim, Tapajoz, is rather poor
and of no great significance. The Museu Nacional has one specimen from
Boim which agrees with the type in the American Museum of Natural
History. The Museum of Comparative Zoology at Harvard College, however,
has one specimen in its collection (MCZ no. 30888 [M]), adult, also from
Boim, in which the color pattern is different although agreement with
the type specimen is shown in cranial characters and width and length of
hairs. This specimen is much darker than the other specimens (of
orange-tint) assigned to this subspecies. However, in other samples of
this species, similarly dark animals have been noted. It seems that the
orange tint is gained only in old age. Another specimen (MCZ no. 30878
[F]) agrees in all respects with the type of the subspecies but the
locality recorded on the label is Cametá, on the Tocantins River.
Possibly the subspecies has a range so wide as to include Cametá but I
suspect that the data on the label is incorrect as to locality. The
collector marked [M] on the label although the specimen is a [F]. The
mistake might have occurred through labeling of specimens at a time
later than that at which they were collected. The collector was in both
localities on more than one occasion.
_Specimens examined._--Total number, 5, from Brazil, Pará, as
follows: _Santarem_, Rio Tapajoz, Boim, 3 (AMNH type, MCZ 1, MN 1);
_Porto de Moz_, Tauarí, 1 (MCZ); _Cametá_ (?) 1 (MCZ).
=Proechimys longicaudatus longicaudatus= (Rengger)
_Echimys longicaudatus_ Rengger, 1830, Naturgeschichte der
Saeugethiere von Paraguay, p. 236.
_Loncheres myosuros_ Lichtenstein, 1832, Darstellung neuer oder
wenig bekannter Säugethiere, pl. 36 and text.
_Echimys myosuros Is._ Geoffroy Saint-Hilaire, 1840, Mag. Zool.,
Ann. 2 (ser. 2):15, 17; Allen, 1899, Bull. Amer. Mus. Nat. Hist.,
12(20):261.
_Echimys cayennensis_ Pictet, 1841, Mém. Soc. Phys. Hist. Nat.,
Genéve, 9:145; Waterhouse, 1848, Nat. Hist. Mammalia, 2:334.
_Proechimys longicaudatus_ Thomas, 1901, Ann. Mag. Nat. Hist., 8
(ser. 7):532; Thomas, 1904, Proc. Zool. Soc. London, p. 240;
Allen, 1916, Bull. Amer. Mus. Nat. Hist., 35(30):569; Tate, 1935,
Bull. Amer. Mus. Nat. Hist., 68(5):400.
_Proechimys cayennensis longicaudatus_ Ellerman, 1940, The
families and genera of living rodents, Brit. Mus. (Nat. Hist.),
1:121; Osgood, 1944, Zool. Ser. Field Mus. Nat. Hist, 29(13):198.
_Type locality._--Northern Paraguay ("unter dem ein und zwansigsten
Breitengrade"). _Type_: Apparently no type specimen was
preserved.
_Range._--Western Mato Grosso, Brazil, and northern Paraguay.
_Diagnosis._--Upper parts almost uniformly Ochraceous-Buff;
incisive foramen widest posteriorly; vomerine sheath complete; p4
and m2 with three counterfolds; m1 and m3 usually with two
counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Dark gray, gradually
blackening toward tip that has long filament; total length 20 to
22 mm; maximum width 0.6 mm. _Setiforms on middorsal region_:
Whitish basally, gradually blackening toward tip but interrupted
by Ochraceous-Buff, subapical zone; blackish tip extended (3.5 mm)
and thin; total length 19 to 20 mm; maximum width 0.06 mm.
_Setiforms on outer thighs_: Whitish basally, progressively
grayish or blackish toward tip but interrupted by Light
Ochraceous-Buff or Ochraceous-Buff, subapical zone; total length
18 to 20 mm; maximum width 0.06 mm.
_Skull._--Slender; supraorbital ridge notably raised; bullae
large, elongate, smooth and inflated; jugals narrow; postorbital
process of zygoma of medium size and constructed entirely of
jugal; incisive foramen wide and large (5.5 x 3 mm), being
wider posteriorly than anteriorly and with posterior margins
raised; vomerine sheath complete, maxillary part slender
and laterally flattened; mesopterygoid fossa extending forward as
far as centers, or anterior margins, of third molars; posterior
palatine foramina on plane with posterior faces, or centers, of
second molars.
_Teeth._--Upper molariform teeth always with three counterfolds.
Lower molariform teeth: p4 and m2 always with three counterfolds,
sometimes the two anterior ones coalesced in m2; m1 with three
counterfolds in one specimen (33 per cent); m3 with only two
counterfolds in all specimens.
_Comparisons._--Differences from _P. l. leucomystax_ and _P. l.
roberti_ are given in the accounts of those subspecies.
_Specimens examined._--Total number, 3 (2 AMNH, 1 CNHM), from
Brazil, Mato Grosso, _Corumbá_, Urucum.
=Proechimys longicaudatus leucomystax= Ribeiro
_Proechimys leucomystax_ Ribeiro, May, 1914, Commissão de linhas
telegraphicas estrategicas de Matto Grosso ao Amazonas, Annexo no.
5. Hit. Nat., Zool., Mammiferos, p. 42, pl. 24 (orig. descr.);
Tate, 1935, Bull. Amer. Mus. Nat. Hist., 68(5):400; Ellerman, 1940,
The families and genera of living rodents, Brit. Mus. (Nat. Hist.),
1:119.
_Type locality._--Utiarití, Rio Papagaio, Diamantion, Mato Grosso,
Brazil. _Type_: Museu Nacional, no. 2212, adult, skull only,
collected on 5 May 1909, by Prof. A. Miaranda Ribeiro, is here
designated _lectotype_. See remarks.
_Range._--Serra dos Parecís, Mato Grosso, Brazil.
_Diagnosis._--Ochraceous-Buff, richly lined with blackish, on
upper parts; some setiforms completely blackened distally;
incisive foramen regularly ovoid; vomerine sheath incomplete;
upper molariform teeth and lower premolar with three counterfolds;
m2 with three counterfolds but m1 and m3 usually with two
counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Grayish basally,
gradually blackening toward tip which is extended as a long
filament; total length 21 to 22 mm; maximum width 0.65 mm.
_Setiforms on middorsal region_: Whitish basally, gradually
blackening toward tip but interrupted by Ochraceous-Buff,
subapical zone; some setiforms grayish basally and gradually
blackening toward distal portion without any colored, subapical
zone; total length 20 to 22 mm, maximum width 0.06 mm. _Setiforms
on outer thigh_: White basally, gradually becoming gray toward tip
but interrupted by Light Ochraceous-Buff, subapical zone; some
setiforms gray basally and blackening toward tip, but interrupted
by Ochraceous-Buff, subapical zone; total length 15 to 18 mm;
maximum width 0.08 mm.
_Skull._--Slender; supraorbital ridges conspicuous; bullae large,
smooth and inflated, with slight, transverse groove; jugals
narrow; postorbital processes of zygomata small and involving only
squamosal; incisive foramen of medium size but narrow (5 x 2.5
mm), regularly oval and with margins uplifted posteriorly;
vomerine sheath incomplete but maxillary part projecting forward
and sometimes almost reaching premaxillary part; mesopterygoid
fossa reaching forward as far as centers of third molars;
posterior palatine foramina at plane of posterior faces of second
molars or slightly anterior thereto.
_Teeth._--Upper molariform teeth with three counterfolds. Lower
molariform teeth: p4 and m2 always with 3 counterfolds; m1 and m3
with 2 counterfolds.
_Comparisons._--From _P. l. longicaudatus_, _leucomystax_ differs
in: upper parts richly lined, instead of scarcely lined, with
blackish; incisive foramen narrower, and regularly oval instead of
widest anteriorly.
_Remarks._--_Proechimys leucomystax_ was described mainly on the
basis of the Utiarití specimen, here designated lectotype of the
species. The specimen from the Juina River is younger, as stated
by Ribeiro in his description. Ribeiro mentions the skin of the
specimen from Utiarití as "em muito mao estado" and I presume it
was discarded as it has not been found in the collection of the
Museu Nacional, Brazil.
_Specimens examined._--Total number, 6, from Brazil, Mato Grosso:
Cáceres, Salto Sepotube, 2 (MN); Cáceres, Tapirapoã, Rio Sepotuba,
2 (AMNH); _Diamantino_, Utiarití, Rio Papagaio, 1 skull (MN);
_Diamantino_, Rio Juina, 1 (MN).
=Proechimys longicaudatus roberti= Thomas
_Proechimys roberti_ Thomas, December, 1901, Ann. Mag. Nat. Hist.,
8 (ser. 7):531 (orig. descr.); Thomas, 1904, Ann. Mag. Nat. Hist.,
14 (ser. 7):195; Thomas, 1921, Ann. Mag. Nat. Hist., 8 (ser.
9):140; Tate, 1935, Bull. Amer. Mus. Nat. Hist., 68(5):400.
_Proechimys cayennensis roberti_ Ellerman, 1940, The families and
genera of living rodents, Brit. Mus. (Nat. Hist.), 1:121.
_Type locality._--Rio Jordão, _Araguarí_, Minas Gerais, Brazil; 960
meters alt. _Type_: British Museum (Nat. Hist.), no. 1.11.3.62, old
male, collected 8 August, 1902, by A. Robert; original number, 705.
_Range._--Western Minas Gerais and southern Goiaz.
_Diagnosis._--Color almost uniformly Ochraceous-Orange on upper
parts; setiforms long and narrow; incisive foramen long and wide;
vomerine sheath usually complete; upper molariform teeth and lower
premolar with three counterfolds; m3 with two, and m1 and m2 with
two or three, counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally,
gradually blackening toward tip; total length, 21 to 23 mm;
maximum width, 0.6 mm. _Setiforms on middorsal region_: Whitish on
basal half, gradually blackening toward tip but interrupted by an
Ochraceous-Orange, subapical zone 6 to 7 mm long; total length 25
to 30 mm; maximum width, 0.05 mm. _Setiforms on outer thighs_:
Whitish on basal half, gradually becoming gray and then blackish
toward tip but interrupted by wide, Ochraceous-Buff, subapical
zone, the tip being brownish or blackish; total length, 22 to 23
mm; maximum width, 0.04 mm.
_Skull._--Slender; supraorbital ridges bent outward and making
sharp angle at point of frontosquamosal suture, then continuing
backward parallel to each other and extending across parietals;
squamosal taking small part in supraorbital ridges; bullae large
(11 x 8 mm), inflated, with shallow depressions; incisive foramen
not especially long but wide (5 x 3 to 3.5 mm), widest in anterior
third and constricted posteriorly; vomerine sheath usually
complete, with maxillary part reduced to slender threadlike
process or, less commonly, missing; mesopterygoid fossa extending
forward as far as centers of third molars; zygomatic arches strong
with jugals of medium dorsoventral width (approximately 3.5 mm);
postorbital process of zygoma weakly developed and involving only
squamosal; posterior palatine foramina on plane of posterior
margins of first molars or slightly anterior thereto.
[Illustration: FIG. 61. Map showing the geographic ranges of the
subspecies of three species of the subgenus _Proechimys_ in Brazil.]
_Teeth._--Upper molariform teeth usually with three counterfolds
(92.5 per cent of 42 specimens); M2 with four counterfolds in 5 per
cent of specimens; M3 with two counterfolds in 2.5 per cent of
specimens. Lower molariform teeth: p4 usually with three
counterfolds (97.5 per cent of 39 specimens); rarely with four (2.5
per cent); m1 with three counterfolds in 58 per cent and two
counterfolds in 42 per cent of specimens; m2 with three
counterfolds in 61 per cent and two counterfolds in 39 per cent of
specimens; m3 always with only two counterfolds.
_Comparisons._--From _P. l. boimensis_, _roberti_ differs in: wider
incisive foramen; lower premolar with three, and one or two lower
molars with only two, counterfolds, instead of lower premolar with
four and all lower molars with three counterfolds. From _P.
longicaudatus_, _roberti_ differs in: upper parts Ochraceous-Orange
instead of Ochraceous-Buff; incisive foramen wider in posterior
third than in anterior third.
_Remarks._--This subspecies seems to be adapted to forests of
post-climactic conditions which is probably typical of most valleys and
margins of the rivers in southern Goiaz and western Minas Gerais. It was
found in Goiaz usually in riparian forests with climactic associations
or in some advanced stage of the sere. The animals also make incursions
into nearby open areas or crops of corn.
_Specimens examined._--Total number, 52, from Brazil, as follows:
Minas Gerais, _Araguarí_, Rio Jordão (effluent of Parnaiba), 960
meters alt., 2 (1 CNHM, 1 DZ); Goiaz, _Anapolis_, 1010 meters alt.,
38 (MN); Goiaz, _Pouso Alto_, 768 meters alt., 11 (MN); Goiaz, Tio
São Miguel, 2 (MN).
=Proechimys guyannensis= (E. Geoffroy)
_Mus guyannensis_ E. Geoffroy Saint-Hilaire, 1803, Catalogue des
mammifères du Museum d'Histoire Naturelle, Paris, p. 194.
_Echimys cayennensis_ Desmarest, 1817, Nouv. Dict. Hist. Nat.,
Paris, nouv. ed., 10:59.
_Proechimys cayennensis_ Allen, 1899, Bull. Amer. Mus. Nat. Hist.,
12(20):261, 264; Tate, 1935, Bull. Amer. Mus. Nat. Hist.,
68(5):399; Ellerman, 1940, The families and genera of living
rodents, Brit. Mus. (Nat. Hist.), 1:120.
_General characters._--Size medium to large; tail usually short;
aristiforms narrow to wide; general color of setiforms on back
ranging from Tawny to Ochraceous-Buff and becoming gradually
lighter on sides; no conspicuous dark longitudinal band on back;
upper parts of hands and feet white to light brown; underparts
white, including inner sides of legs; skull elongate and not
conspicuously ridged; vomerine sheath complete or incomplete; upper
premolar with three counterfolds and molars with two or three;
lower premolar with three or four counterfolds, and lower molars
with two or three.
=Proechimys guyannensis villicauda= subspecies nova
_Type locality._--Tapirapoã, Rio Sepotuba, _Cáceres_, Mato Grosso,
Brazil. _Type_: Museu Nacional, no. 1932, adult male (color faded);
collected on 2 February, 1909, by Prof. A. Miranda Ribeiro;
original number, 788 A.
_Range._--Serra dos Parecís, headwaters of Paraguai and Tapajoz
rivers.
_Diagnosis._--Aristiforms wide and stiff; general color on upper
parts Ochraceous-Orange; incisive foramen long; vomerine sheath
incomplete or complete; lower premolar with four counterfolds,
remaining molariform teeth with three counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally,
gradually becoming gray toward tip, with distal fourth blackish
and ending as a long filament; total length, 22 to 23 mm; maximum
width, 1 mm. _Setiforms on middorsal region_: Whitish on basal
half, gradually blackening toward tip but interrupted by
Ochraceous-Orange, subapical zone 5 mm long; total length, 26 to
30 mm; width, 0.04 to 0.12 mm. _Setiforms on outer thighs_: Whitish
on basal half, gradually blackening toward tip but interrupted by
Ochraceous-Buff to Ochraceous-Orange subapical zone; total length
20 to 23 mm; width, 0.03 to 0.18 mm.
_Skull._--Strong; supraorbital ridges raised and extending across
anterior fourth of parietals; nasals elongate; bullae rounded,
inflated, with shallow grooves; postorbital process of zygoma
weakly developed and constructed entirely of jugal; incisive
foramen elongate and narrow (5.5 x 2.5 mm), posteriorly constricted
with posterior margins elevated above surface of bones; vomerine
sheath incomplete or complete but, when complete, with maxillary
part filiform and delicate; mesopterygoid fossa extending forward
as far as middle, or even anterior, parts of third molars;
posterior palatine foramina on plane of centers, or even anterior
faces, of second molars.
_Teeth._--Upper molariform teeth with three counterfolds. Lower
molariform teeth: premolar with four counterfolds, molars with
three counterfolds, sometimes with two folds coalesced in center
of tooth.
_Comparison._--From _P. g. ribeiroi_, and _P. g. bolivianus_,
_villicauda_ differs in wider aristiforms. From _P. g. ribeiroi_,
_villicauda_ further differs in: larger and wider incisive
foramen; vomerine sheath incomplete or complete instead of always
complete and thick. From _P. g. bolivianus_, _villicauda_ differs
in: lower premolars always, instead of rarely, with four
counterfolds, and m3 always with three counterfolds instead of
usually with only two counterfolds.
_Specimens examined._--Total number, 4, from Brazil, Mato Grosso,
as follows: _Cáceres_, Tapirapoã, 3 (MN); _Diamantino_, Rio
Papagaio, Utiarití, 1 (AMNH).
[Illustration: FIG. 62.
_Proechimys guyannensis villicauda_, male, MN no. 1932, Tapirapoã.
Type. × 1.]
[Illustration: FIG. 63. _Proechimys guyannensis ribeiroi_, male, MN no.
1935, Rio Doze de Outubro. Type. × 1.]
[Illustration: FIG. 64. _Proechimys guyannensis hyleae_, male, MCZ no.
30887, Tauarí. Type. × 1.]
[Illustration: FIG. 65. _Proechimys guyannensis nesiotes_, male, CNHM
no. 19496, Ilha de Manapirí. Type. × 1.]
[Illustration: FIG. 66. _Proechimys guyannensis leioprimna_, female,
CNHM no. 19503, Cametá. Type. × 1.]
[Illustration: FIG. 67. _Proechimys guyannensis oris_, male, CNHM no.
19495, Providencia. × 1.]
[Illustration: FIG. 68. _Proechimys guyannensis arescens_, male, CNHM
no. 26440, Fazenda Inhuma. Paratype. × 1.]
[Illustration: FIG. 69. _Proechimys guyannensis riparum_, female, AMNH
no. 143018, Manaus. Type. × 1.]
[Illustration: FIG. 70. _Proechimys guyannensis arabupu_, male, AMNH no.
75816, Arabupu. Type. × 1.]
[Illustration: FIG. 71. _Proechimys guyannensis villicauda_, male, MN
no. 1932, Tapirapoã. Type. × 1.]
[Illustration: FIG. 72. _Proechimys guyannensis ribeiroi_, male, MN no.
1935, Rio Doze de Outubro. Type. × 1.]
[Illustration: FIG. 73. _Proechimys guyannensis hyleae_, male, MCZ no.
30887, Tauarí. Type. × 1.]
[Illustration: FIG. 74. _Proechimys guyannensis nesiotes_, male, CNHM
no. 19496, Ilha de Manapirí. Type. × 1.]
[Illustration: FIG. 75. _Proechimys guyannensis leioprimna_, female,
CNHM no. 19503, Cametá. Type. × 1.]
[Illustration: FIG. 76. _Proechimys guyannensis oris_, male, CNHM no.
19495, Providencia. × 1.]
[Illustration: FIG. 77. _Proechimys guyannensis arescens_, male, CNHM
no. 26440, Fazenda Inhuma. Paratype. × 1.]
[Illustration: FIG. 78. _Proechimys guyannensis riparum_, female, AMNH
no. 143018, Manaus. Type. × 1.]
[Illustration: FIG. 79. _Proechimys guyannensis arabupu_, male, AMNH no.
75816, Arabupu. Type. × 1.]
[Illustration: FIGS. 80, 81. _Proechimys guyannensis villicauda_, male,
MN no. 1932, Tapirapoã. Type. × 1.]
[Illustration: FIGS. 82, 83. _Proechimys guyannensis ribeiroi_, male, MN
no. 1935, Rio Doze de Outubro. Type. × 1.]
[Illustration: FIGS. 84, 85. _Proechimys guyannensis hyleae_, male, MCZ
no. 30887, Tauarí. Type. × 1.]
[Illustration: FIGS. 86, 87. _Proechimys guyannensis nesiotes_, male,
CNHM no. 19496, Ilha de Manapirí. Type. × 1.]
[Illustration: FIGS. 88, 89. _Proechimys guyannensis leioprimna_,
female, CNHM no. 19503. Type. × 1.]
[Illustration: FIGS. 90, 91. _Proechimys guyannensis oris_, male, CNHM
no. 19495, Providencia. × 1.]
[Illustration: FIGS. 92, 93. _Proechimys guyannensis arescens_, male,
CNHM no. 26440, Fazenda Inhuma. Paratype. × 1.]
[Illustration: FIGS. 94, 95. _Proechimys guyannensis riparum_, female,
AMNH no. 143018, Manaus. Type. × 1.]
[Illustration: FIGS. 96, 97. _Proechimys guyannensis arabupu_, male,
AMNH no. 75816, Arabupu. Type. × 1.]
=Proechimys guyannensis ribeiroi= subspecies nova
_Type locality._--Rio 12 de Outubro, affluent of the Camararé,
_Mato Grosso_, Mato Grosso, Brazil; about 190 kilometers west of
Utiarití; altitude 414 meters. _Type_: Museu Nacional, no. 1935,
adult male (colors faded); collected on 20 June, 1909, by Prof. A.
Miranda Ribeiro; original number _G._
_Range._--Known only from the type locality.
_Diagnosis._--_Aristiforms wide and stiff_; incisive foramen small
and narrow; vomerine sheath complete and thick; p4 with four
counterfolds; remaining molariform teeth with three counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally,
gradually blackening toward tip; total length, 19 to 22 mm;
maximum width, 0.8 mm. _Setiforms on middorsal region_: Whitish on
basal half, gradually blackening toward tip but interrupted by
subapical zone probably of some tint of ochraceous; total length,
22 to 24 mm; maximum width, 0.06 mm. _Setiforms on outer thighs_:
Whitish basally, gradually blackening toward tip but interrupted
by probably light ochraceous, subapical zone; total length 14 to
16 mm; maximum width, 0.03 mm.
_Skull._--Slender; supraorbital ridges low; bullae ovate with
shallow grooves; postorbital process of zygoma almost obsolete and
involving mostly jugal; incisive foramen short and narrow (4 × 2
mm), constricted posteriorly and with posterior margins raised;
vomerine sheath complete and thick; mesopterygoid fossa extending
forward as far as posterior faces of second molars; posterior
palatine foramina on plane with centers of second molars.
_Teeth._--Upper molariform teeth with three counterfolds. Lower
molariform teeth: p4 with four counterfolds; molars with three
counterfolds which sometimes are fused.
_Comparisons._--From _P. g. bolivianus_, _ribeiroi_ differs in:
aristiforms wider; incisive foramen shorter and narrower; vomerine
sheath complete and thick, instead of complete or incomplete and
not thick; p4 always with four, instead of usually only three,
counterfolds and lower molars always with three, instead of
sometimes with only two, counterfolds in m3. Differences from _P.
g. villicauda_ are given in the account of that subspecies.
_Remarks._--The name _ribeiroi_ is given in honor of the late Professor
Alipio Miranda Ribeiro, in recognition of his important work in
Brazilian vertebrate zoology.
_Specimens examined._--Total number, 2 (MN), from Brazil, Mato
Grosso, _Mato Grosso_, Rio 12 de Outubro; altitude, 414 meters.
=Proechimys guyannensis hyleae= subspecies nova
_Type locality._--Tauarí, Rio Tapajoz, _Porto de Moz_, Pará,
Brazil; approximately 87 kilometers south of Santarem. _Type_:
Museum of Comparative Zoology at Harvard College, no. 30887, adult
male; collected on 19 January, 1934, by A. M. Olalla; original
number 7288.
_Range._--Region of lower Tapajoz River and banks of Amazon up to
the Jamundá River.
_Diagnosis._--Aristiforms conspicuously wide and stiff; general
color on upper parts Tawny; incisive foramen long and oval;
vomerine sheath complete but with maxillary part slender or,
sometimes, incomplete; p4 with four counterfolds, rarely three;
remaining molariform teeth with three counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally,
gradually becoming blackish toward tip; total length, 19 to 21 mm;
maximum width, 1.1 mm. _Setiforms on middorsal region_: a. Gray
basally, gradually blackening toward tip but interrupted by wide (5
to 6 mm) Tawny, subapical zone; some are whitish basally and
gradually become sooty brown toward tip except for same type of
subapical zone (tip only slightly darker than subapical zone); b.
With the same type described above and some completely blackish,
with the base gray; total length 22 to 25 mm; maximum width, 0.1
mm. _Setiforms on outer thighs_: Whitish basally, gradually
becoming gray and then blackish toward tip but interrupted by long,
Ochraceous-Tawny, subapical zone; tip, itself, blackish brown;
sometimes this type appears with some lighter ones and sometimes
with completely blackish setiforms; total length 16 to 18 mm;
maximum width 0.3 mm.
_Skull._--Medium in size and slender; cranium narrow and not
increasing much in breadth posteriorly; rostrum stout, laterally
thick, with masseteric crest well-developed; nasals pointed
posteriorly; supraorbital ridges broad but barely extended across
parietals; zygomatic arches strong; postorbital process of zygoma
involving mostly squamosal; incisive foramen long and narrow (5.5
to 6 × 2.5 mm), oval and extending posteriorly to point only 2 mm
anterior to premolars; vomerine sheath complete with maxillary
part usually slender; mesopterygoid fossa extending forward as far
as centers of third molars; bulla of medium size, well inflated
and with shallow grooves on surface.
_Teeth._--Upper molariform teeth with three counterfolds. Lower
premolar with four counterfolds or, sometimes (20 per cent of 15
specimens), with only three; lower molars with three counterfolds.
_Comparisons._--From _P. g. oris_ and _P. g. nesiotes_, _hyleae_
differs in: wider aristiforms; general color on upper parts Tawny,
instead of Ochraceous-Orange; vomerine sheath not always complete,
instead of always complete. From _P. g. oris_, _hyleae_ differs
in: p4 usually with four, instead of only three counterfolds and
all molars with three, instead of only lower molars with three
counterfolds. From _P. g. nesiotes_, _hyleae_ differs in: p4
usually, instead of always, with four counterfolds; color on back
Tawny instead of Ochraceous-Orange; aristiforms wider.
_Remarks._--This subspecies shows greater variability than any other in
this species. There are two types of coloration. The most common type of
coloration is dark, with Tawny, subapical zones in the setiforms of the
middorsal region and many completely black setiforms; in the other type
the subapical zone is still Tawny but there are no black setiforms. One
specimen from Obidos, on the north bank of the Amazon, completely agrees
in the characteristics of color and skull with the reddish type and
suggests either that there is an extension of the range of the
subspecies along the lower course of the Tapajoz or that there are two
subspecies, in which event the animals from Tauarí are intergrades
between _hyleae_ and an unnamed, tawny-colored subspecies occurring to
the southward.
Between 13 and 23 January, 1934, A. M. Olalla collected 10 adult
females, 6 of which contained embryos. Three of the females had 2
embryos each, two had 3 embryos each and one had only 1 embryo. At this
same time and place only ten per cent of specimens obtained were not
fully adult.
_Specimens examined._--Total number, 21, from Brazil, Pará, as
follows: _Porto de Moz_, Tauarí, right bank of Tapajoz,
approximately 85 kilometers south of Santarem, 20 (19 MCZ, 1 CNHM);
_Obidos_, Obidos, 1 (MCZ).
=Proechimys guyannensis nesiotes= subspecies nova
_Type locality._--Ilha de Manapirí, Rio Tocantins, Pará,
Brazil. _Type_: Chicago Natural History Museum, no. 19496, adult
male; collected on 9 December, 1910, by Dr. Emilia Snethlage;
original number, 12.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms wide and stiff; general color on upper
parts Ochraceous-Orange; incisive foramen long, with parallel
borders; vomerine sheath complete and thick; p4 with four
counterfolds, remaining molariform teeth with three counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length, 18 to 19 mm;
maximum width, 0.9 mm. _Setiforms on middorsal region_: Gray
basally, gradually blackening toward tip but interrupted by
Ochraceous-Orange, subapical zone 4 mm long; total length 16 to 19
mm; maximum width, 0.06 mm. _Setiforms on outer thighs_: Whitish
basally, gradually becoming gray and blackish toward tip but
interrupted by Ochraceous-Buff, subapical zone 3 mm long; total
length, 13 to 15 mm; maximum width, 0.03 mm.
_Skull._--Of medium size; rostrum short; nasals pointed
posteriorly; postorbital ridges extending caudad across anterior
fifth of parietals; zygomatic arches strong; jugal with process in
posterior part of masseteric fossa; postorbital process of zygoma
involving mostly squamosal; incisive foramen elongate, narrow (5 x
2.3 mm), and parallel sided; posterior margin of incisive foramen
approximately 3 mm anterior to premolars; margins of foramen
raised to form ridges; vomerine sheath complete, of almost uniform
width and set deeply in foramen; mesopterygoid fossa extending
forward as far as centers of third molars; bullae of medium size
and inflated.
_Teeth._--Upper molariform teeth with three counterfolds; p4 with
four counterfolds; m1-3 with three counterfolds.
_Comparison._--_From P. g. oris_, _nesiotes_ differs in:
Aristiforms conspicuously wider; incisive foramen shorter and
narrower, with borders parallel instead of posteriorly
constricted; posterior margin of incisive foramen farther from
premolars; p4 with four, instead of three, counterfolds; lower
molars with three instead of two counterfolds. From _P. g.
leioprimna_, _nesiotes_ differs in: Incisive foramen with parallel
borders instead of oval; p4 with four instead of three
counterfolds; m3 always with three instead of two counterfolds.
_Remarks._--Dr. E. Snethlage mentions the type as having been collected
at night in the forest.
_Specimens examined._--Total number, 8 (MCZ, CNHM, MN), from
Brazil, Pará, Tocantins River, Ilha de Manapirí.
=Proechimys guyannensis leioprimna= subspecies nova
_Type locality._--Cametá, left bank of Tocantins River, near its
mouth, Cametá, Pará, Brazil. _Type_: Chicago Natural History
Museum, no. 19503, adult female; collected on 21 January, 1911, by
Dr. Emilia Snethlage; original number, 35.
_Range._--Known only from type locality but probably extending
westward toward Xingú River.
_Diagnosis._--Aristiforms wide and stiff; general color on upper
parts Ochraceous-Orange, incisive foramen moderately long; oval;
vomerine sheath complete; all molariform teeth with three
counterfolds, except lower, third molar which has only two.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip which is extended as a short
filament; total length, 19 to 21 mm; maximum width, 0.8 to 1 mm.
_Setiforms on middorsal region_: Whitish basally, gradually
blackening toward tip but interrupted by Ochraceous-Orange,
subapical zone 2 to 3 mm long; total length, 17 to 20 mm; maximum
width 0.1 mm. _Setiforms on outer thighs_: Whitish basally,
becoming gradually gray and then blackish toward tip but
interrupted by Ochraceous-Buff, subapical zone; blackish tip
short; total length 13 to 15 mm; maximum width 0.06 mm.
_Skull._--Of medium size; rostrum relatively short; nasals with
posterior borders rounded; postorbital ridges extending across
anterior fourth of parietals; zygomatic arches moderately strong;
postorbital process of zygoma involving both jugal and squamosal;
incisive foramen of medium length (4 to 5 mm) and narrow (about
2.5 mm), oval and extending caudad to a plane approximately 2 mm
anterior to premolars; vomerine sheath complete, with premaxillae
forming approximately anterior 3/4 of sheath; maxillary part of
sheath short but well-developed; mesopterygoid fossa extending
forward as far as centers of third molars; bullae of medium size
but well-inflated.
_Teeth._--Upper molariform teeth with three counterfolds. Lower
molariform teeth with three counterfolds, except third molar which
has only two.
_Comparison._--From _P. g. oris_, _leioprimna_ differs in:
conspicuously wider aristiforms; shorter and narrower incisive
foramen; lower molariform teeth with three counterfolds (except m3
with only two), instead of lower molars with only two
counterfolds. Differences from _P. g. nesiotes_ are given in the
account of that subspecies.
_Remarks._--The paratype was collected in an "igarapé," depression
usually invaded by the river waters; the paratype, collected on 18
January, 1911, had two large embryos.
_Specimens examined._--Total number, 4 (2 CNHM, 2 AMNH), from
Brazil, Pará, Cametá.
=Proechimys guyannensis oris= Thomas
_Proechimys oris_ Thomas, September, 1904, Ann. Mag. Nat. Hist., 14
(ser. 7): 195; Thomas, 1905, Ann. Mag. Nat. Hist., 15 (ser. 7):587;
Thomas, 1912, Ann. Mag. Nat. Hist., 9 (ser. 8):89; Tate, 1935,
Bull. Amer. Mus. Nat. Hist., 68:400; Osgood, 1944, Zool. Ser. Field
Mus. Nat. Hist., 29:199.
_Proechimys cayennensis oris_ Ellerman, 1940, The families and
genera of living rodents, Brit. Mus. (Nat. Hist.), 1:121.
_Type locality._--Igarapé-assú, E. F. B., near Belem, Igarapé-assú,
Pará, Brazil. _Type_: British Museum (Nat. Hist.), no. 4.7.4.78,
old male; collected on 6 March, 1904, by Alphonse Robert; original
number, 1818.
_Range._--Probably most of the region on south bank of Amazon
River, between Tocantins (west) and Gurupí River (south).
_Diagnosis._--Aristiforms narrow but somewhat stiff; color on
upper parts Ochraceous-Orange; incisive foramen long and wide,
conspicuously constricted posteriorly; posterior margin of incisive
foramen close to plane of premolars; vomerine sheath complete but
maxillary part threadlike; upper molariform teeth and lower
premolar with three counterfolds; lower molars with only two
counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip, which is extended as a filament;
total length, 16 to 17 mm; maximum width, 0.6 to 0.7 mm.
_Setiforms on middorsal region_: Gray basally, gradually becoming
blackish toward tip but interrupted by Ochraceous-Orange,
subapical zone 2 to 4 mm long; total length, 18 to 20 mm; maximum
width 0.06 mm. _Setiforms on outer thighs_: Whitish basally,
gradually becoming blackish toward tip but interrupted by
Ochraceous-Buff, subapical zone; total length, 15 to 16 mm;
maximum width, 0.04 mm.
_Skull._--Of medium size; supraorbital ridges well developed and
extending across anterior fifth of parietals; zygomatic arches
strong; jugal with masseteric fossa deep and with well-developed
posterior process; postorbital zygomatic process involving mostly
squamosal; incisive foramen long (6 to 7 mm), widest anteriorly
(2.5 to 3.2 mm); but narrowing posteriorly to less than 1 mm and
extending caudad almost to plane of premolars; vomerine sheath
complete but maxillary part delicate and threadlike; mesopterygoid
fossa extending forward as far as third molars or posterior parts
of second molars; bullae large and inflated.
_Teeth._--Each upper molariform tooth with three counterfolds. In
lower jaw, premolar with three, and molars with only two,
counterfolds.
_Comparisons._--Differences from the subspecies with adjoining
ranges are given in the accounts of those subspecies.
_Remarks._--Thomas (1912:89) extended the known range of the subspecies
to Faro, on the Jamundá River, on the left bank of the Amazon, and to
Boim, on the Tapajoz River, as well as to Benevides, E. F. Braganca,
near Belem. It seems to me that the specimens from Faro should be
referred provisionally to _Proechimys guyannensis hyleae_; the specimens
from Boim are "more brightly rufous" (Thomas, _loc. cit._) and could be
referred to Allen's _P. boimensis_, described in 1914, but _P.
guyannensis hyleae_ probably lives in the same place and only an
examination of the specimens, which I have not seen, would permit of
certainly allocating the specimens to their correct species. The
specimens from Benevides are more certainly _P. g. oris_.
E. Snethlage collected one specimen in a garden (Providencia, E. F. B.).
However, according to the personnel of the Brazilian Health Service, the
animals are strictly forest dwellers although they do make excursions
into more open places.
_Specimens examined._--Total number, 3, from Brazil, Pará, as
follows: Providencia, E. F. B., approximately 15 kilometers east
from Belem, 1 (CNHM); Tanaquará, near Belem, 1 (MN); Rio Guamá,
near Belem, 1 (AMNH).
_Additional record._--Brazil, Pará, Benevides, E. F. B.,
approximately 100 kilometers north-east of Belem (Thomas,
1912:89).
=Proechimys guyannensis arescens= Osgood
_Proechimys cayennensis arescens_ Osgood, 12 July 1944, Zool. Ser.
Field Mus. Nat. Hist., 29(13): 198.
_Type locality._--Fazenda Inhuma, below Santa Filomena, upper Rio
Parnaiba, _Vitoria do Alto Parnaiba_, Maranhão, Brazil. _Type_:
Chicago Natural History Museum, no. 26441, adult male; collected on
5 August, 1925, by Heinrich E. Snethlage.
_Range._--Region including the valleys of the Turí-assú and
Parnaiba rivers, Maranhão, Brazil.
_Diagnosis._--Aristiforms moderately wide and not conspicuously
stiff; general color of upper parts near (15'a) Ochraceous-Orange;
incisive foramen long and wide; vomerine sheath complete or
incomplete; upper molariform teeth and lower premolar with three
counterfolds; lower molars with only two.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally,
gradually blackening toward tip; total length, 19 to 21 mm;
maximum width, 0.7 mm. _Setiforms on middorsal region_: Whitish
basally or on basal half, gradually becoming gray and then
blackish toward tip, but interrupted by long (5 to 6 mm) subapical
zone near (15'_a_) Ochraceous-Orange; total length, 15 to 16 mm;
maximum width 0.05 mm. _Setiforms on outer thighs_: Whitish on
basal half, gradually becoming gray and then blackish toward tip
but interrupted by Ochraceous-Buff, subapical zone; tip sometimes
not conspicuously darker than subapical zone; total length 18 to
25 mm; maximum width, 0.03 mm.
_Skull._--Medium in size, not elongated; nasals pointed
posteriorly; supraorbital ridges strong and thick, extending
caudad across anterior third of parietals; zygomatic arches
strong; postorbital process of zygoma involving only squamosal;
incisive foramen 5 by 2.7 mm, oval and extending caudad to plane
approximately 2 mm anterior to premolars; posterior margins of
incisive foramen not forming a ridge; vomerine sheath complete and
with maxillary part slender and threadlike, or incomplete, in
which event, maxillary part not extended enough to join
premaxillary process; mesopterygoid fossa extending forward
as far as centers of third molars; bulla large and more or less
triangular in its peripheral outline.
_Teeth._--Upper molariform teeth with three counterfolds each.
Lower premolar with three counterfolds; lower molars with two
counterfolds.
_Comparisons._--From _P. g. oris_, _arescens_ differs in: Color of
upper parts lighter and more uniform; incisive foramen oval
instead of conspicuously constricted posteriorly; posterior margin
of incisive foramen farther from premolars.
_Remarks._--One specimen from Turí-assú (MN) has been identified by O.
Thomas as "_P. oris_" (his own handwriting is on the label) and the
subspecies is really closely related to _oris_.
_Specimens examined._--Total number, 3, from Brazil, Maranhão, as
follows: _Vitoria do Alto Parnaiba_, Fazenda Inhuma (below Santa
Filomena), 2 (CNHM); Alto da Alegria, Turí-assú, 1 (MN).
=Proechimys guyannensis riparum= subspecies nova
_Type locality._--Manaus, _Manaus_, Amazonas, Brazil. _Type_:
American Museum of Natural History, no. 143018, adult female;
collected 6 March, 1943.
_Range._--Known only from type locality but probably extending
northward and eastward.
_Diagnosis._--Aristiforms wide and stiff; upper parts
Ochraceous-Tawny; incisive foramen short, wide, and oval; vomerine
sheath incomplete; upper molariform teeth and lower premolar with
three counterfolds; lower molars with only two counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Gray basally
gradually blackening toward tip; total length, 18 to 20 mm;
maximum width, 0.9 mm. _Setiforms on middorsal region_: Whitish
basally, gradually blackening toward tip but interrupted by 2 mm
long, Ochraceous-Tawny, subapical zone; total length 20 to 22 mm;
maximum width, 0.04 mm. Some are whitish basally and gradually
become black toward tip with no subapical zone. _Setiforms on
outer thighs_: Whitish basally, gradually becoming gray and then
blackish toward tip but interrupted by Ochraceous-Buff, subapical
zone 3 to 4 mm long; tip not conspicuously dark; total length, 17
to 19 mm; maximum width, 0.03 mm.
_Skull._--Of medium size and slender; rostrum slender; nasals
rounded posteriorly; supraorbital ridges well developed and barely
extended onto anteriormost part of parietals; zygomatic arches
slender; infraorbital foramen with well-developed groove for nerve
transmission; postorbital process of zygoma almost obsolete and
involving mostly squamosal; incisive foramen short and wide (4.5 ×
3.3 mm), oval and with posterior margins raised to form ridges
which extend toward premolars; posterior margin of incisive
foramen approximately 2.5 mm anterior to premolars; vomerine
sheath incomplete, with only short, premaxillary part;
mesopterygoid fossa extending forward as far as anterior
parts of third molars; bullae large and inflated, with more or
less triangular outline.
_Teeth._--Crown length of well worn P4-M3, 6.8 mm; upper
molariform teeth with three counterfolds each. Lower premolar
with three counterfolds; lower molars with two counterfolds.
[Illustration: FIG. 98. Map showing the geographic ranges of the
subspecies of _Proechimys guyannensis_ in Brazil.]
_Comparisons._--From _P. g. oris_ and _P. g. hyleae_, _riparum_
differs in: Shorter and wider incisive foramen; vomerine sheath
incomplete, instead of sometimes incomplete. From _P. g. oris_,
_riparum_ differs in: Upper parts Ochraceous-Tawny instead of
Ochraceous-Orange; aristiforms conspicuously wider. From _P. g.
hyleae_, _riparum_ differs in: Aristiforms narrower; upper parts
Ochraceous-Tawny instead of Tawny; lower premolars with three,
instead of four, counterfolds; lower molars with two, instead of
three, counterfolds.
_Specimens examined._--Type only.
=Proechimys guyannensis arabupu= subspecies nova
_Type locality._--Arabupu, Mount Roraima, _Bõa Vista_, Territ. Rio
Branco; about 1540 meters altitude. _Type_: American Museum of
Natural History, no. 75816, adult male; collected by Dr. G. H. H.
Tate on 30 December, 1927; original number, 4716.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms conspicuously wide and stiff; color on
upper parts dark, near (15'_j_) Ochraceous-Tawny; incisive foramen
widest in anterior third; vomerine sheath complete, sometimes
incomplete; upper molariform teeth and lower premolar with three
counterfolds; lower molars with two counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Whitish basally,
gradually blackening toward tip; total length, 19 to 22 mm;
maximum width, 1.1 mm. _Setiforms on middorsal region_: Gray
basally, gradually blackening toward tip but interrupted by dark
(15'j) Ochraceous-Tawny, subapical zone 3 mm long; some completely
blackish on distal parts; total length, 20 to 23 mm; maximum
width, 0.07. _Setiforms on outer thighs_: Whitish basally,
gradually blackening toward tip but interrupted by Ochraceous-Buff
or Light Ochraceous-Buff, subapical zone; total length, 20 to 23
mm; maximum width, 0.07 mm.
_Skull._--Size medium; nasals pointed posteriorly; supraorbital
ridges prominent and slightly extended caudad onto anterior half
of parietals; groove for transmission of nerve in infraorbital
foramen weakly developed; zygomatic arches strong; postorbital
process of zygoma involving mostly squamosal; incisive foramen
approximately 5.5 × 2.7 mm, widest in anterior third and
constricted posteriorly, with posterior margin about 1 mm anterior
to plane of premolars; vomerine sheath complete, with premaxillary
part expanded and maxillary part notably slender and sometimes
lacking; mesopterygoid fossa in some specimens extending forward
as far as middle parts of second molars; bullae large and
inflated.
_Teeth._--Upper molariform teeth with three counterfolds each.
Lower premolar with three counterfolds; molars with only two.
_Comparisons._--From _P. g. warreni_, _arabupu_ differs in:
Narrower aristiforms; narrower incisive foramen; lower premolar
with three instead of four counterfolds; lower molars with two,
instead of three, counterfolds. From _P. g. oris_, _arabupu_
differs in: Aristiforms wider; posterior margin of incisive
foramen farther from plane of premolars; upper parts dark (15'_j_)
Ochraceous-Tawny, instead of Ochraceous-Orange.
_Remarks._--The sample is fairly uniform.
_Specimens examined._--Total number, 6 (AMNH), from Brazil,
Territorio do Rio Branco, Bõa Vista, Mount Roraima, Arabupu;
approximately 1540 m. altitude.