_Type._--Male, subadult, skin and skull; No. 36976, Univ.
Kansas Mus. Nat. Hist.; 70 km. [by highway] S Ciudad
Victoria and 6 km. W of the [Pan-American] highway [at El
Carrizo], Tamaulipas, Mexico; 14 January 1950; obtained by
William J. Schaldach, Jr., original no. 578.
_Range._--Known only from the type locality; probably found
in other localities along the humid, east face of the Sierra
Madre Oriental in Tamaulipas.
_Diagnosis._--Size large (see measurements); upper parts
dusky brown, paler on sides, individual hairs on middle of
back tipped with black or with Light Pinkish Cinnamon
(capitalized color term after Ridgway, Color Standards and
Color Nomenclature, Washington, D. C., 1912); head grayer
especially on cheeks; underparts dusky (dark bases of
white-tipped hairs exposed), hairs on throat and inguinal
region of adult specimen white to base; outside of legs
dusky gray; tail scaly in appearance and sparsely covered
with short, blackish hairs above and short, whitish hairs
below; skull with auditory bulla large; external auditory
meatus large; palatine region narrow; sides of
interpterygoid fossa concave and broadly excavated near
posterior end of molariform tooth-rows.
_Comparison._--_Neotoma angustapalata_ has been compared
with _N. torquata_ (specimens from Veracruz and Puebla), _N.
navus_ (Coahuila), _N. mexicana_ (New Mexico), _N. micropus_
(Tamaulipas), _N. albigula_ (Coahuila), _N. ferruginea_
(Jalisco), and _N. distincta_ (from published description in
Goldman, N. Amer. Fauna, 31:64, October 19, 1910). _Neotoma
angustapalata_ differs from _N. micropus_ and _N. albigula_
in having a deep, instead of a shallow, anterointernal
reentrant angle on the first upper molar and seems to belong
to the _N. mexicana_ group of wood rats. _Neotoma
angustapalata_ differs from _N. navus_, _N. mexicana_, _N.
torquata_, and _N. ferruginea_ in larger size, darker
underparts, tail with sparse, short hairs and scaly
appearance, more broadly concave sides of interpterygoid
fossa at posterior end of molariform tooth-rows, larger
external auditory meatus, and narrower palatine breadth.
_Neotoma angustapalata_ differs from the description of _N.
distincta_ in having a faintly bicolored tail, no ochraceous
pectoral band, broadly concave sides to interpterygoid
fossa, and narrower palatine breadth.
_Remarks._--_Neotoma angustapalata_ is represented by two specimens;
the type and another specimen, an adult male, no. 37062, with skin and
broken skull. The description takes into account both of these
specimens. The most significant characteristics of _N. angustapalata_
are its scaly-appearing tail with short, sparse hairs, dusky
underparts, broadly concave sides of the interpterygoid fossa at the
posterior end of molariform tooth-rows, and the narrow palatine
breadth. Among named kinds of _Neotoma_, the newly named species most
closely resembles _N. torquata_ and _N. distincta_; however, it is
geographically widely separated from these two species. _Neotoma navus_
of southeastern Coahuila is the only other member of the _N. mexicana_
group in northeastern Mexico.
These wood rats were taken in rocks and crevices at the base of a small
hill in thick vegetation growing in deep humus. Schaldach termed the
trapping site as "arid tropical tending toward humid tropical".
_Measurements._--The subadult, male holotype measures as
follows: Total length, 325; length of tail, 154; length of
hind foot, 36; length of ear from notch, 29; basilar length
(of skull), 33.9; zygomatic breadth, 22.1; interorbital
breadth, 5.7; length of nasals, 15.2; length of incisive
foramina, 8.7; length of palatal bridge, 8.5; least breadth
of palate between first upper molars, 2.7; greatest breadth
of interpterygoid space, 4.1; alveolar length of upper
molariform tooth-row, 9.6. The adult, male, no. 37062,
measures as follows: Total length, 380; tail vertebrae, 195;
hind foot, 42; ear from notch, 31; interorbital breadth (of
skull), 6.4.
_Specimens examined_, 2, from the type locality.
~Rattus rattus~ subsp.