_Oryzomys melanotis_ occurs in Tamaulipas from Soto la Marina
southward. Two subspecies are recorded: _O. m. carrorum_ in the north
and _O. m. rostratus_ in the tropical area from Rancho Pano Ayuctle to
Altamira.
Specimens from the Sierra de Tamaulipas were trapped along a stream,
edged with trees, bushes and rocks; at Rancho Pano Ayuctle the animals
were in grass between banana groves. The specimen from 70 kilometers
south of Ciudad Victoria was taken in tall grass near a field of sugar
cane in a line of traps that yielded also _Peromyscus leucopus_,
_Sigmodon hispidus_, _Liomys irroratus_, and _Oryzomys fulvescens_.
Hooper (1953:8) and Ingles (1959:395) reported _O. melanotis_ as caught
at the edges of cane fields.
=Oryzomys melanotis carrorum= Lawrence
1947. _Oryzomys rostratus carrorum_ Lawrence, Proc. New
England Zool. Club, 24:101, May 29, type from Rancho Santa
Ana, about 8 mi. SW Padilla, Rio Soto la Marina, Tamaulipas.
1959. _Oryzomys melanotis carrorum_, Hall and Kelson, The
Mammals of North America, 2:560, March 21.
_Distribution in Tamaulipas._--Southeast part of state;
known only from the type locality and the Sierra de
Tamaulipas.
The original description of this subspecies was based on three
specimens collected at Rancho Santa Ana. Specimens examined from the
Sierra de Tamaulipas extended the known range 45 miles southeast of the
type locality, and also extend the previously known altitudinal range
of 300-350 feet elevation to 1200 feet.
Specimens examined correspond in color and measurements to those
recorded by Lawrence (1947:102-103). Of 12 specimens studied, the
tympanic bullae of six touch the surface of the table when the skull
rests on the tips of the incisors and the occipital condyles. In the
other six the bullae are 0.3 to 1.3 mm. above the table top. The
mesopterygoid space in the specimens examined are broad and U-shaped
and not V-shaped as in the three specimens examined by Lawrence (_op.
cit._). Weight of six males was 52.5 (48-63) and of four females 44.7
(40-49) grams.
_Measurements._--Average and extreme measurements of six
males are as follows: 255.3 (240-269); 135.7 (120-147);
135.7 (120-147); 30.4 (30-31); 21 (20-22); greatest length
of skull, 31.6 (30.9-32.5); zygomatic breadth, 15.3
(14.7-16.1); interorbital constriction, 4.8 (4.5-5.1);
breadth of skull, 31.6 (30.9-32.5); length of nasals, 12.9
(12.4-13.4); length of anterior palatine foramina, 5.5
(5.2-5.7); length of palatal bridge, 6.1 (5.8-6.4); length
of maxillary tooth-row, 4.0 (3.9-4.1). The females average
slightly smaller.
_Records of occurrence._--Specimens examined, 12 from Sierra
de Tamaulipas, 10 mi. W, 2 mi. S Piedra, 1200 ft.
Additional record: Type locality (Lawrence, 1947:102).
=Oryzomys melanotis rostratus= Merriam
1901. _Oryzomys rostratus_ Merriam, Proc. Washington Acad.
Sci., 3:293. July 26, type from Metlatoyuca, Puebla.
1953. _Oryzomys melanotis rostratus_, Hooper, Occ. Papers
Mus. Zool., Univ. Michigan, 544:8, March 25.
_Distribution in Tamaulipas._--Extreme southeastern part of
state, in tropical area.
Ingles (1959:395) reported one specimen from two miles north of Ciudad
Mante as _O. melanotis_; here it is referred to _O. m. rostratus_ on
geographic grounds.
_Records of occurrence._--Specimens examined, 2: 2 km. W El
Carrizo, 1; Rancho Pano Ayuctle, 25 mi. N El Mante and 3 km.
W Highway, 1.
Additional records: 2 mi. N Cd. Mante (Ingles, 1959:395);
Altamira (Goldman, 1918:54).
=Oryzomys alfaroi huastecae= Dalquest
1951. _Oryzomys alfaroi huastecae_ Dalquest, Jour.
Washington Acad. Sci., 41:363, November 14, type from 10 km.
E Platanito, San Luis Potosi.
_Distribution in Tamaulipas._--Known only from Rancho del
Cielo (Hooper, 1953:8).
=Oryzomys fulvescens=