_Genotype._--_Echimys albispinus_ Is. Geoffroy Saint-Hilaire, 1838;
by original designation.
_Trinomys_ Thomas, July 1921, Ann. Mag. Nat. Hist., 8 (ser. 9):140
(orig. descr.); Tate, 1935, Bull. Amer. Mus. Nat. Hist.,
68(5):401; Ellerman, 1940, The families and genera of living
rodents, Brit. Mus. (Nat. Hist.), 1:115.
[Illustration: FIG. 99. Map showing the geographic ranges of the
subspecies of three species of the subgenus _Trinomys_.]
_General characters._--Pelage of upper parts with lanceolate and,
sometimes, clavate aristiforms extending over most of rump and onto
thighs; tail 86 to 103 per cent of length of head and body; tail
sometimes white-tipped and sometimes penicillate; skull small, with
ridges moderately developed; supraorbital ridges involving no part
of parietals; infraorbital foramen with no separate groove for
transmission of nerve; mesopterygoid fossa extending forward to
level of second or first molars; incisors opisthodont, orthodont or
proodont; molariform teeth, in occlusal view, with main fold large
and usually reaching opposite wall; no counterfold anterior to main
fold in upper molariform teeth and usually no counterfold posterior
to main fold in lower molariform teeth; premolars larger than first
molars, first molars larger than second molars and second molars
larger than third molars; four molariform teeth of nearly equal
size in some animals.
Thomas (1921:140) erected the subgenus _Trinomys_, including in it
the species _albispinus_ and _setosus_ and stated that "the primary
distinction between these [_Trinomys_ and _Proechimys_] lies in the
number of laminae present in the cheekteeth--four in _Proechimys_,
three in _Trinomys_." The distinction is valueless as a subgeneric
character, not only because the character is not constant in the
species in the subgenus but also because there is subspecific
variation in number of laminae in the cheekteeth. _Proechimys
albispinus_, however, shares with three other species common
characters, as listed above, and the name _Trinomys_ will,
therefore, apply to this group of species, since _Proechimys
albispinus_ is the genotype.
=Proechimys dimidiatus= (Günther)
_Echimys dimidiatus_ Günther, 1 April 1877, Proc. Zool. Soc.
London, 1876(4):747.
_Proechimys dimidiatus_ Allen, 1899, Bull. Amer. Mus. Nat. Hist.,
12(20):264; Ribeiro, 1905, Arch. Mus. Nac. Rio de Janeiro, 13:187;
Thomas, 1921, Ann. Mag. Nat. Hist., 8 (ser. 9):141; Tate, 1935,
Bull. Amer. Mus. Nat. Hist., 68(5):400; Ellerman, 1940, The
families and genera of living rodents, Brit. Mus. (Nat. Hist.),
1:122.
_Type locality._--Unknown; probably southwestern Rio de Janeiro,
Brazil (see Remarks). _Type_: British Museum (Nat. Hist.), no.
51.7.21.24; presented by Lord Derby.
_Range._--Rio de Janeiro, from the southern limit of the state
northward to and including the Distrito Federal.
_General characters._--Size large; tail averaging 80 per cent of
head and body; aristiforms narrow and soft (0.4 to 0.5 mm wide),
imparting a non-spiny character to the pelage; general color of
upper parts Ochraceous-Buff, finely lined with blackish brown,
gradually becoming lighter on sides; ventral surface of body and
inner sides of legs white; feet dorsally white but with a
sepia-colored stripe along outer margin; tail brownish-black above
and white below, but white sometimes extended to upper side in
distal part; skull broad with no conspicuous ridges; jugals deep
with transverse ridge usually conspicuous; postorbital process of
zygoma involving only squamosal; incisive foramen short and wide
posteriorly; vomerine sheath complete in 95 per cent of specimens
and with maxillary part thick; posterior palatine foramina at
plane of first molars or slightly anterior to them; bullae
moderately developed; in juvenal specimens, each upper molariform
tooth with three counterfolds, but posteriormost counterfold
small; in adult specimens, posteriormost counterfold
disappearing in 50 per cent of fourth premolars and first molars,
in 20 per cent of second molars, and in 15 per cent of third
molars; lower molariform teeth with two counterfolds in almost
every juvenal specimen, this number, in adult animals, decreasing
in m3 to one in 20 per cent of specimens but rarely being reduced
in other teeth.
_General characters._--Aristiforms soft and narrow, ranging from 15
to 19 mm in total length and 0.4 to 0.5 mm in maximum width; pelage
generally non-spiny and not harsh; length of tail ranging from 20
per cent shorter than head and body to as long as, or slightly
longer than, head and body; ears rather small (23 to 25 mm).
[Illustration: FIGS. 100-103. _Proechimys dimidiatus_, male, MN no.
5452, Tijuca. × 1.]
_Color._--General color of back and sides results from uniform
mixture of black distal parts of aristiforms with Ochraceous-Buff
of subapical zone of setiforms. Dorsally, from nose caudad to rump,
mixture appears brownish-black, lined with Ochraceous-Buff; toward
sides, amount of Ochraceous-Buff gradually increases and resultant
color is much lighter brown than on back. On outer parts of arms
and legs, color turns gradually to sepia toward distal parts and
finally to uniform sepia on wrists and ankles, this color extending
to outer dorsal parts of hands and feet; on ankles, sepia forms
complete ring, as usual in the genus. Tail blackish-brown on upper
parts, this stripe gradually tapering toward tip where dark brown
hairs form small pencil; white of under side of tail sometimes seen
also entirely around distal part, short of tip which remains dark
brown. Ventral surfaces wholly white, from upper lips caudad
including inner surfaces of legs.
_Hairs._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip that has long, fine filament;
total length 16 to 19 mm; maximum width 0.5 mm. On outer thigh
whitish basally, gradually blackening toward tip; some with
Ochraceous-Buff, subapical zone; total length 13 to
15 mm; maximum width 0.25 mm. _Setiforms on middorsal region_:
Whitish on basal half, gradually blackening toward tip, but
interrupted by Ochraceous-Buff, subapical zone; some with Light
Ochraceous-Buff, subapical zone and short, blackish zone on tip;
total length 12 to 14 mm; maximum width 0.02 mm. _Setiforms on
outer thighs_: Whitish on basal half, then gradually becoming gray
on middle part and finally Light Ochraceous-Buff on distal third,
or with tip blackish and Ochraceous-Buff, subapical zone.
_Skull._--Elongate and broad with no conspicuous crests; rostrum
rather stout; jugals deep with transverse crest usually
well-developed; zygomatic postorbital process conspicuous and
formed entirely of squamosal; incisive foramen short and wide
posteriorly; vomerine sheath complete in great majority of
specimens, its maxillary part wide and strong; posterior palatine
foramina on plane with front of M1 or slightly farther forward;
bullae rather small and elongate.
_Teeth._--P4 with three secondary folds in all juvenal specimens,
but posteriormost fold small and disappearing in 50 per cent of
adult specimens; M1 with 3 outer folds in juveniles and also
disappearing in 50 per cent of adults; M2 with three outer folds
in juveniles, but only 20 per cent remaining in adults; M3 with 3
outer folds in 50 per cent of juveniles, decreasing to 15 per cent
in adults. Lower molariform teeth: p4 with 2 secondary folds; m1
with 2 secondary folds in 90 per cent of adults and in all
juveniles; m2 with 2 secondary folds in 98 per cent of adults and
in all juveniles; m3 with 2 secondary folds in 81 per cent of
adults, remaining percentage with only one counterfold, and with 2
secondary folds in all juveniles.
_Remarks._--Samples studied of _P. dimidiatus_ are notably uniform
throughout the geographic range of the species. The few biotypes
detected seemed unworthy of subspecific rank.
In discussing the type locality of the species, Thomas (1921:141)
states: "We know that its donor did obtain a number of specimens from
Rio Janeiro, and the skull agrees so closely with those of two examples
from Itatiaia, near to the Rio-Minas frontier, collected and presented
by Prof. J. P. Hill, that I have no hesitation in referring the latter
to Günther's species."
_Specimens examined._--Total number, 211 (MN), from Brazil as
follows: Rio de Janeiro; _Parati_, Pedra Branca (400 m.), 113;
_Mangaratiba_, Fazenda do Rubião (750 m.), 3; Fazenda do Tenente
(700 m.), 4; Fazenda da Lapa (450 m.), 13; _Teresópolis_, Fazenda
Guinle (960 m.), 61; _Nova Iguassú_, Barro Branco (20 m.), 16;
Distrito Federal, Tijuca, 1.
_Additional records._--Rio de Janeiro, Itatiaia (Thomas,
1921:141); Rio de Janeiro, Zona da mata, Mont-Serrat, Serra do
Itatiaia (Ribeiro, 1905:187).
=Proechimys iheringi= Thomas
_General characters._--Size large; tail long; aristiforms generally
wide and stiff; general color on upper parts and sides a
combination of blackish from tips of aristiforms with cinnamon
ground color from subapical zones of setiforms; darker band on
middorsal line; differentiated light-colored aristiforms
conspicuous on outer sides of thighs and rump; usually rufous tint
on neck and postauricular region; underparts white; tail with white
tip, usually accentuated by white brush; feet white on dorsal
surface; hind feet slightly darker on outer sides; skull elongate
and smooth; jugals wide dorso-ventrally; incisive foramen elongate;
upper molariform teeth usually with one to five counterfolds, number
varying with subspecies; lower premolar always with two counterfolds
and lower molars always with one or two counterfolds.
_Remarks._--As a whole, the samples of the populations of the species do
not afford a satisfactory record of the distribution; my concept of the
group may be changed when further collections are made in localities
geographically intermediate between those from which specimens now are
known. If some of the forms prove to be physiologically isolated, they
may deserve treatment as full species according to the conventional
standards of systematic zoology. _P. panema_, for example, does not seem
to be geographically isolated from _P. gratiosus_. _P. denigratus_, at
the northernmost known occurrence of the species, actually represents a
striking jump in the cline, although collections from intermediate
regions may provide intermediate structural stages. Further collecting
may also prove that the southern form, _P. iheringi iheringi_, is
completely isolated from the rest of the group. However, these samples
are certainly more related to each other than any one of them is to that
of the other species found in the same range, namely _P. dimidiatus_,
and all the forms in question, therefore, seem best arranged as
subspecies of one full species. A clinal variation certainly exists
among these forms and the most striking differences correspond to larger
geographical distances.
[Illustration: FIG. 104. _Proechimys iheringi iheringi_, female, MN no.
6453, Ilha de São Sebastião. × 1.]
[Illustration: FIG. 105. _Proechimys iheringi bonafidei_, male, MN no.
6183, Fazenda Bõa Fé. Type. × 1.]
[Illustration: FIG. 106. _Proechimys iheringi gratiosus_, male, MN no.
4024, Floresta da Caixa Dagua. Type. × 1.]
[Illustration: FIG. 107. _Proechimys iheringi panema_, female, MN no.
8288, Campinho. Type. × 1.]
[Illustration: FIG. 108. _Proechimys iheringi denigratus_, male, MN no.
8500, Mata do Ribeirão da Fortuna. Type. × 1.]
[Illustration: FIG. 109. _Proechimys iheringi paratus_, female, MN no.
4012, Floresta da Capela de São Braz. Type. × 1.]
[Illustration: FIG. 110. _Proechimys iheringi iheringi_, female, MN no.
6453, Ilha de São Sebastião. × 1.]
[Illustration: FIG. 111. _Proechimys iheringi bonafidei_, male, MN no.
6183, Fazenda Bõa Fé. Type. × 1.]
[Illustration: FIG. 112. _Proechimys iheringi gratiosus_, male, MN no.
4024, Floresta da Caixa Dagua. Type. × 1.]
[Illustration: FIG. 113. _Proechimys iheringi panema_, female, MN no.
8288, Campinho. Type. × 1.]
[Illustration: FIG. 114. _Proechimys iheringi denigratus_, male, MN no.
8500, Mata do Ribeirão da Fortuna. Type. × 1.]
[Illustration: FIG. 115. _Proechimys iheringi paratus_, female, MN no.
4012, Floresta da Capela de São Braz. Type. × 1.]
[Illustration: FIGS. 116, 117. _Proechimys iheringi iheringi_, female,
MN no. 6453, Ilha de São Sebastião. × 1.]
[Illustration: FIGS. 118, 119. _Proechimys iheringi bonafidei_, male, MN
no. 6183, Fazenda Bõa Fé. Type. × 1.]
[Illustration: FIGS. 120, 121. _Proechimys iheringi gratiosus_, male, MN
no. 4024, Floresta da Caixa Dagua. Type. × 1.]
[Illustration: FIGS. 122, 123. _Proechimys iheringi panema_, female, MN
no. 8288, Campinho. Type. × 1.]
[Illustration: FIGS. 124, 125. _Proechimys iheringi denigratus_, male,
MN no. 8500, Mata do Ribeirão da Fortuna. Type. × 1.]
[Illustration: FIGS. 126, 127. _Proechimys iheringi paratus_, female, MN
no. 4012, Floresta da Capela de São Braz. Type. × 1.]
=Proechimys iheringi iheringi= Thomas
_Proechimys iheringi_ Thomas, August, 1911, Ann. Mag. Nat. Hist., 8
(ser. 8):252 (orig. descr.); Thomas, 1921, Ann. Mag. Nat. Hist., 8
(ser. 9):141; Tate, 1935, Bull. Amer. Mus. Nat. Hist., 68(5):400;
Ellerman, 1940, The families and genera of living rodents, Brit.
Mus. (Nat. Hist.), 1:122.
_Type locality._--Island of São Sebastião (off São Paulo), Formosa,
São Paulo, Brazil. _Type_: British Museum (Nat. Hist.), no.
2.8.25.5, adult male, presented by the São Paulo Museum.
_Range._--Littoral and islands of São Paulo and Rio de Janeiro.
_Diagnosis._--Aristiforms narrow; tail shorter than head and body;
setiforms Cinnamon-Buff; incisive foramen short; vomerine sheath
complete; upper molariform teeth with two or three counterfolds;
lower molariform teeth with two counterfolds, rarely one in m3.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length 18 to 23 mm; maximum
width, 0.6 mm. _Aristiforms on outer thighs_: Gray basally,
blackening distally toward tip; some differentiated with
Cinnamon-Buff tip. _Setiforms on middorsal region_: Gray basally,
gradually blackening toward tip but interrupted by a
Cinnamon-Buff, subapical zone 3 mm long; total length, 16 to 20
mm; maximum width, 0.06 mm. _Setiforms on outer thighs_: Gray
basally, gradually blackening toward tip but interrupted by
Cinnamon-Buff, subapical zone or with Cinnamon-Buff continuous to
tip.
_Skull._--Slender; bullae small and well inflated; jugal
dorso-ventrally wide with transverse ridge inconspicuous; incisive
foramen short, 3.5 × 2.5 mm; vomerine sheath complete;
mesopterygoid fossa extending forward as far as middle parts of
second molars; postorbital process of zygoma small, formed by both
jugal and squamosal; posterior palatine foramina at plane of
premolars; interorbital breadth narrow.
_Teeth._--Upper molariform teeth with two or three counterfolds
(when unworn usually three and rarely four); sometimes only one
counterfold in M3 and sometimes counterfolds fused in molars.
Lower molariform teeth with two counterfolds, rarely one in m3.
_Comparisons._--From _P. i. bonafidei_ and _P. i. gratiosus_,
_iheringi_ differs in: Incisive foramen shorter; vomerine sheath
complete, instead of usually incomplete; setiforms Cinnamon-Buff,
instead of Ochraceous-Buff; upper molariform teeth with two or
three separate counterfolds, instead of having counterfolds fused
or reduced to one or two; aristiforms narrower in _iheringi_ than
in _bonafidei_.
_Specimens examined._--Total number, 25, from Brazil, as follows:
São Paulo, _Formosa_, Ilha de São Sebastião, 9 (DZ 6, MN 2, MCZ 1);
São Paulo, _Mogi das Cruzes_, Alto da Serra, alt. 900 m., 2 (DZ);
São Paulo, _Ubatuba_, alt. 10 m., 4 (2 DZ, 2 MN); Rio de Janeiro,
_Angra dos Reis_, 2 (MN); Rio de Janeiro, _Angra dos Reis_, Ilha
Grande, 7 (5 DZ, 1 MCZ, 1 MN).
=Proechimys iheringi bonafidei= subspecies nova
_Type locality._--Fazenda Bõa Fé, _Teresópolis_, Rio de Janeiro,
Brazil; alt. 850 meters. _Type_: Museu Nacional, no. 6183, adult
male; collected on 18 August, 1942, by G. Pereira; SEPFA no. M
14663.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms wide and stiff; tail shorter than head
and body; setiforms Ochraceous-Buff; incisive foramen long;
vomerine sheath incomplete, or rarely complete; molariform teeth
with two counterfolds usually fused.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length, 22 to 26 mm;
maximum width, 0.8 mm. _Aristiforms on outer thighs_: Gray
basally, gradually blackening toward tip but interrupted by
Ochraceous-Buff subapical zone; some Ochraceous-Buff to tip; total
length, 18 to 20 mm; maximum width, 0.7 mm. _Setiforms on
middorsal region_: Gray basally, gradually blackening toward tip
but interrupted by Ochraceous-Buff, subapical zone; total length,
17 to 20 mm; maximum width, 0.06 mm. _Setiforms on outer thighs_:
Gray basally, gradually blackening toward tip but interrupted by
Ochraceous-Buff, subapical zone; only a short blackened tip.
_Skull._--Large, with elongate rostrum; bullae large and well
inflated; jugals with transverse ridge inconspicuous; postorbital
process of zygoma small, formed mostly by squamosal; incisive
foramen elongated (5.5 × 2.5 mm); vomerine sheath incomplete or,
if complete, with maxillary part thin and delicate; posterior
palatine foramen at plane of first molars; mesopterygoid fossa
extending forward as far as middle parts of second molars.
_Teeth._--Upper molariform teeth with two counterfolds; these
completely separated in 3 of 16 specimens; two counterfolds
coalesced in all three molars in 6 specimens; counterfolds
coalesced in only two molars in 3 specimens; counterfolds
coalesced in only one molar in 4 specimens. Lower molariform teeth
with two counterfolds which are completely separated in 13 of 16
specimens; counterfolds coalesced in only one molar in 2
specimens; counterfolds coalesced in all three molars in one
specimen.
_Comparisons._--From _P. i. gratiosus_, _bonafidei_ differs in:
Aristiforms wider; tail shorter; molariform teeth with two
counterfolds instead of one or two. Differences from _P. i.
iheringi_ are given in the account of that subspecies.
_Remarks._--Of females with embryos two were captured in April and one
in September. The embryos number 2, 1, 2. Young were captured mostly in
April, but two were taken in July. Male gonads seemed to be most active
in March, April and September. The animals lived in a second growth
forest, approaching the climax. The rainfall was more than 1600 mm
annually, and the mean annual temperature was 18.5° centigrade.
_Specimens examined._--Total number, 18 (MN), from Brazil, Rio de
Janeiro, _Teresópolis_, Fazenda Bõa Fé.
=Proechimys iheringi gratiosus= subspecies nova
_Type locality._--Floresta da Caixa Dagua, _Santa Teresa_, Espirito
Santo, Brazil; altitude 750 meters. _Type_: Museu Nacional, no.
4024, adult male; collected on 25 May, 1940, by C. Lako; SEPFA no.
M 6911.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms narrow; tail of same length as head and
body; setiforms Ochraceous-Buff; incisive foramen long; vomerine
sheath usually incomplete; upper molariform teeth with one or two
counterfolds; lower molariform teeth with two counterfolds, except
that m3 usually has only one.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length, 21 to 27 mm; maximum
width, 0.6 mm. _Aristiforms on outer thighs_: Gray basally,
gradually blackening toward middle, and Ochraceous-Buff on distal
half; total length, 18 to 21 mm; maximum width, 0.5 mm. _Setiforms
on middorsal region_: Gray basally, gradually blackening toward tip
but interrupted by short, Ochraceous-Buff, subapical zone; total
length, 18 to 20 mm; maximum width, 0.06 mm. _Setiforms on outer
thighs_: Gray basally, gradually blackening toward middle, and
distal part Ochraceous-Buff or with only tip blackened; total
length, 14 to 16 mm; maximum width, 0.05 mm.
_Skull._--Slender; bullae small but well-inflated; upper edge of
jugals deeply concave; transverse ridge of jugals conspicuous;
postorbital process of zygoma small, involving only squamosal;
incisive foramen elongate (5 x 2.5 mm); vomerine sheath almost
always incomplete, and maxillary part lacking or, when present,
slender; mesopterygoid fossa extending forward as far as middle of
second molars; posterior palatine foramina at plane of front
border of first molars or slightly anterior thereto.
_Teeth._--Upper molariform teeth with two counterfolds in 10 of 16
specimens and only one in remainder; these folds commonly
coalesced; M3 with only one counterfold in 6 specimens, and 2
counterfolds in remainder. Lower molariform teeth with two
counterfolds in 6 specimens and in 10 of them m3 has only one
counterfold.
_Comparisons._--From _P. i. panema_, _gratiosus_ differs in: Lower
molariform teeth with only one counterfold in smaller percentage
of specimens; incisive foramen shorter; aristiforms narrower;
setiforms Ochraceous-Buff instead of Cinnamon. Differences from
_iheringi_ and _paratus_ are given in the accounts of those
subspecies.
_Remarks._--All the animals were captured in climax forest.
_Specimens examined._--Total number, 16 (MN), from Brazil, Espirito
Santo, _Santa Teresa_, Floresta da Caixa Dagua, altitude 750
meters.
=Proechimys iheringi panema= subspecies nova
_Type locality._--Campinho, _Colatina_, Espirito Santo, Brazil;
altitude 500 meters. _Type_: Museu Nacional, no. 8288, adult
female; collected on 15 July, 1942, by C. Lako.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms moderately wide; tail of approximately
same length as head and body; setiforms Cinnamon; incisive foramen
moderately long and narrow; vomerine sheath incomplete; upper
molariform teeth with two counterfolds, but m3 most frequently
with one.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length, 21 to 23 mm;
maximum width, 0.8 mm. _Aristiforms on outer thighs_: Gray, some
gradually blackening toward tip and others with distal part
Cinnamon; total length, 17 to 19 mm; maximum width, 0.7 mm.
_Setiforms on middorsal region_: Gray, gradually blackening
toward tip, but interrupted by Cinnamon, subapical zone; total
length, 18 to 20 mm; maximum width, 0.06 mm. _Setiforms on outer
thighs_: Gray, gradually blackening toward middle, and Cinnamon on
all of distal parts or with tip blackish; total length, 13 to 15
mm; maximum width, 0.09 mm.
_Skull._--Strong, with jugals dorso-ventrally wide; interorbital
region and cranium wide; bullae well inflated; transverse ridge of
jugals not well-developed; postorbital process of zygoma small and
formed only of squamosal; incisive foramen 4.7 × 2.2 mm; vomerine
sheath always incomplete, with maxillary part reduced to small
process; mesopterygoid fossa extending forward as far as middle of
second molars or only slightly short thereof; posterior palatine
foramina at plane of front of first molars.
_Teeth._--All upper molariform teeth with two counterfolds in 4
specimens; one having only one counterfold in M3; 3 with
counterfolds coalesced in one or two molars. Lower molariform
teeth with two counterfolds in one specimen, these counterfolds
not coalesced; m3 with one counterfold in 4 specimens and with two
in one specimen.
_Comparisons._--Differences from _P. denigratus_ and _P. i.
paratus_ are given in the accounts of those animals.
_Specimens examined._--Total number, 5 (MN), from Brazil, Espirito
Santo, _Colatina_, Campinho; altitude 500 meters.
=Proechimys iheringi denigratus= subspecies nova
_Type locality._--Mata do Ribeirão da Fortuna, 40 kilometers west
of Ilheus, _Itabuna_, Bahia, Brazil. _Type_: Museu Nacional, no.
8500, adult male; collected 16 March, 1945.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms wide and stiff; tail longer than head
and body; setiforms near (15''_a_) Cinnamon; incisive foramen long
and narrow; vomerine sheath complete; premolars with two
counterfolds, upper molars with one or two, and lower molars with
only one.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length, 20 to 22 mm;
maximum width, 1.1 mm. _Aristiforms on outer thighs_: Gray
basally, gradually blackening toward tip or with distal part near
(15''_a_) Cinnamon; total length, 14 to 16 mm; maximum width, 0.5
mm. _Setiforms on middorsal region_: Gray basally, gradually
blackening toward tip but interrupted by near (15''_a_) Cinnamon,
subapical zone 4 mm wide; total length, 18 to 20 mm; maximum
width, 0.05 mm. _Setiforms on outer thighs_: Gray basally,
gradually blackening toward tip but interrupted by wide, near
(15''_a_) Cinnamon, subapical zone.
_Skull._--Slender; nasals short; bullae large and well-inflated;
jugals with conspicuous transverse ridge; postorbital process of
zygoma conspicuous, spiniform and formed almost exclusively by
jugal; incisive foramen elongated and narrow (5 × 1.8 mm);
vomerine sheath complete and formed almost exclusively by
premaxillae; maxillary part of this sheath short and in most
specimens the two parts of sheath completed by vomer itself;
mesopterygoid fossa extending forward as far as middle of second
molars and in some skulls as far as anterior border of second
molars; posterior palatine foramina at anterior plane of first
molars.
_Teeth._--Upper molariform teeth: P4 always with two counterfolds;
M1 with two counterfolds in 65 per cent of specimens but anterior
counterfold poorly developed; rest of specimens with only one
counterfold in M1; M2 with two counterfolds in 50 per cent of
specimens and only one in remainder; M3 with two counterfolds in
only 17 per cent of specimens, and remainder with only one. Lower
molariform teeth: p4 always with two counterfolds; molars always
with only one counterfold.
_Comparisons._--From _P. i. panema_, _denigratus_ differs in: Each
lower molar with only one, instead of with more than one,
counterfold; incisive foramen longer and narrower; vomerine sheath
complete instead of incomplete; aristiforms conspicuously wider;
tail longer.
_Remarks._--One female (SEPFA no. M 17060) captured on 9 January, 1944,
gave birth to two females on 26 January, 1944. Each of these young
measured 177 mm in total length and weighed 27.8 g. On 4 March, 1944,
their measurements were: head and body, 120,120; tail, 120,130; hind
foot, 32,33; ear, 21,22; skull:--total length, 36.0,35.0;
condyloincisive length, 29.0,29.1; zygomatic breadth, 19.1,18.5; length
of nasals, 12.5,11.6; interorbital constriction, 9.3,8.8; cranial
breadth, 16.4,16.9; palatilar length, 11.5,10.5; crown length of P4 and
M1, 4.3,4.3 mm.
The forest where the animals were captured has a high percentage of
deciduous trees in spite of the heavy rainfall in this region. All of
the animals were trapped near water. Young were captured from January to
May. Most animals have a conspicuous Cinnamon patch on the nuchal
region.
_Specimens examined._--Total number, 34 (SEPFA 33, MN 1), from
Brazil, Bahia, _Itabuna_, Mata do Ribeirão da Fortuna.
=Proechimys iheringi paratus= subspecies nova
_Type locality._--Floresta da Capela de São Braz, _Santa Teresa_,
Espirito Santo, Brazil; altitude 630 meters. _Type_: Museu
Nacional, no. 4012, adult female; collected on 24 September, 1940,
by Dr. H. W. Laemmert; SEPFA no. M 8447.
_Range._--Known only from the type locality.
_Diagnosis._--Aristiforms wide and stiff; tail 96 per cent of head
and body; color on setiform Cinnamon-Buff; incisive foramen short
and moderately wide; vomerine sheath complete; all molariform
teeth with two counterfolds.
_Pelage._--_Aristiforms on middorsal region_: Gray basally,
gradually blackening toward tip; total length, 24 to 26 mm;
maximum width, 1.3 mm. _Aristiforms on outer thighs_: Gray
basally, gradually blackening toward middle, and distal parts near
(15''_c_) Pinkish Cinnamon; total length, 18 to 20 mm; maximum
width 0.8 mm. _Setiforms on middorsal region_: Gray basally,
gradually blackening toward tip but interrupted by Cinnamon-Buff,
subapical zone; total length 14 to 16 mm; maximum width, 0.06 mm.
_Skull._--Slender; bullae large and well-inflated; jugals with
conspicuous, transverse ridge; postorbital process of zygoma
moderately developed and involving only squamosal; incisive
foramen short and narrow (4.1 × 2.1 mm); vomerine sheath complete,
with maxillary part short and thick; mesopterygoid fossa extending
forward as far as posterior parts of second molars; posterior
palatine foramina at plane of premolars.
[Illustration: FIG. 128. Map showing the geographic ranges of the
subspecies of _Proechimys iheringi_.]
_Teeth._--Upper and lower molariform teeth with two counterfolds.
Counterfolds coalesced in P4 and M1 of one specimen.
_Comparisons._--From _P. i. gratiosus_ and _P. i. panema_,
_paratus_ differs in: all molariform teeth with two, instead of
some with fewer, counterfolds; vomerine sheath complete and thick
instead of usually incomplete; incisive foramen shorter and
narrower; aristiforms conspicuously wider; setiforms Cinnamon-Buff
instead of Ochraceous-Buff and Cinnamon, respectively. Tail 96 per
cent of head and body in _paratus_ instead of 100 per cent as in
_panema_.
_Remarks._--The animals were captured in climax forest.
_Specimens examined._--Total number, 3 (MN), from Brazil, Espirito
Santo, _Santa Teresa_, Floresta da Capela de São Braz; altitude 630
meters.