Two males from Jaumave weighed 62 and 65 and one pregnant female weighed 67 grams.
Most records of O. p. peragrus are from places along the Sierra Madre Oriental, but Lawrence (1947:103) recorded a specimen from the Río Corona, which is east of, but not far from the mentioned Sierra. Baker (1951:215) reported two specimens from two different localities labeled with reference to Ciudad Victoria (same specimens reported here) as O. p. aquaticus, but pointed out that they tended "toward the darker O. c. peragrus." Examination of more material and taking into consideration the relation between the interorbital constriction and the greatest length of skull, cause me here to refer those specimens to peragrus.
Hooper (1953:8) reported three young specimens from Rancho Pano Ayuctle as of the subspecies aquaticus, but study of two adults from the same locality reveals that this locality should be included within the geographic range of peragrus.
Records of occurrence.—Specimens examined, 9: 36 km. N, 10 km. W Cd. Victoria, 1; Jaumave, 2400 ft., 5; Rancho Pano Ayuctle, 25 mi. N, 3 km. W El Mante, 2; 70 km. S Cd. Victoria (by highway) and 6 km. W of Highway, 1.
Additional records: Río Corana (Lawrence, 1947:103); Pano Ayuctle (Hooper, 1953:8).
Oryzomys melanotis
Black-eared Rice Rat
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, Río Soto la Marina, Tamaulipas.