_Distribution in Tamaulipas._--West of Sierra Madre Oriental.
The six specimens examined were collected in the desert area west of the Sierra Madre Oriental. At Nicolas a trap set in front of a hole held one specimen, and another was trapped beneath a brush fence that inclosed a cornfield. _Dipodomys merriami_ and _Perognathus penicillatus_ also were trapped beneath the fence.
A subadult from Nicolas is slightly larger (see measurements) than either of two subadults from four miles north of Jaumave and an old specimen from eight miles north of Tula, except in the interorbital constriction, which is narrower. Nevertheless measurements of Tamaulipan _Onychomys torridus_ resemble those given by Hollister (1914:483) for _O. t. subrufus_. A specimen from Nicolas is also darker than other individuals examined.
A female taken on July 15, four miles north of Jaumave, was lactating.
_Measurements._--Measurements of a female from Nicolas, a male from eight miles north of Tula, and a female and a male from four miles north of Jaumave are as follows: 158, 147, 145, 144; 59, 58, 55, 55; 22, 21, 22, 22; 21, 20.5, 18, 18; condylobasal length, 24.4, 23.1, 23.9, 23.7; interorbital constriction, 4.1, 4.4, 4.3, 4.5; length of nasals, 10.6, 10.5, 10.5, 10.1; length of maxillary tooth-row, 3.8, 3.6, 3.7, 3.7; breadth of braincase, 11.8, 11.3, 11.3, 11.0; weight in grams, 32.5, 26.0, 25.0, 25.0.
_Records of occurrence._--Specimens examined, 6: 4 mi. N Jaumave, 2; Nicolas, 56 km. NW Tula, 5500 ft., 2; Tajada, 23 mi. NW Tula, 5200 ft., 1; 8 mi. N Tula, 4500 ft., 1.
Additional records (Hollister, 1914:475): Miquihuana; Jaumave.
=Sigmodon hispidus=
Hispid Cotton Rat
This species, as is known, is active by day and by night. It occurs mainly in gra.s.sy areas and most of the specimens examined were trapped there. But, one mile east of La Pesca, specimens were taken on a beach having spa.r.s.e gra.s.s. _Neotoma micropus_ and _Spermophilus spilosoma_, but no smaller rodents, were taken there. Also, many crabs were found in the traps. Possibly only the relatively large rodents are able to compete successfully with the crabs. The specimen from one kilometer east of El Barretal was caught in a rat-trap set in front of small hole in a fence of dead brush that surrounded a cornfield. The area outside the fence supported mesquite and ebony trees (10-12 feet high) and the ground was covered with cat claw. Six miles north and six miles west of Altamira, the two young specimens were taken on a small gra.s.sy island surrounded by mud.
According to natives, _Sigmodon_ injures corn and sugar cane. Probably other species of rodents are responsible for some or all of such damage since other kinds of rodents were taken in the same areas.
Dice (1937:245) reported females from the Sierra San Carlos that carried 8 embryos of 18 mm., 5 33, 7 embryos very small, and 8 20.
Females were collected on July 22, 29, and 30.
=Sigmodon hispidus berlandieri= Baird
1855. _Sigmodon berlandieri_ Baird, Proc. Acad. Nat. Sci.
Philadelphia, 7:333, type from Rio Nazas, Coahuila.
1902. _Sigmodon hispidus berlandieri_, V. Bailey, Proc.
Biol. Soc. Washington, 15:106, June 2.
_Distribution in Tamaulipas._--From Jaumave and Llera to north.
This subspecies is distinguished from _S. h. toltecus_ by larger size and paler, grayish coloration.
TABLE 3.--DATA ON REPRODUCTION.
=========================+=============+=========+============= LOCALITYDateEmbryosSize in mm.
-------------------------+-------------+---------+------------- 4 mi. N La PescaMay 26430 Sierra de TamaulipasJune 10310 Sierra de TamaulipasJune 11410 Sierra de TamaulipasJune 20220 Ciudad VictoriaJuly 1255 JaumaveJuly 28414 JaumaveJuly 29625 San FernandoAugust 30720 San FernandoAugust 31811 Vicinity of Nuevo LaredoNovember 1535 Vicinity of Nuevo LaredoNovember 1652 -------------------------+-------------+---------+-------------
Baker (1951:216) reported a specimen from 35 kilometers north and 10 kilometers west of Ciudad Victoria (= 1 km. E El Barretal) as _S. h.
toltecus_. Comparison of its skull with those from the vicinity of Altamira (_S. h. toltecus_) and those from Jaumave (_S. h.
berlandieri_) shows that the skull from El Barretal closely resembles those from Jaumave, in having the zygomatic arches more nearly parallel and the braincase more rounded than in skulls from Altamira.
Therefore the specimen from the vicinity of El Barretal is here a.s.signed to _S. h. berlandieri_.
_Records of occurrence._--Specimens examined, 64: 4-1/2 mi.
S Nuevo Laredo, 600 ft., 1; 10 mi. S, 11 mi. E Nuevo Laredo, 8; San Fernando, 180 ft., 8; 4 mi. N La Pesca, 10; 3 mi. N La Pesca, 1; 1 mi. E La Pesca, 3; Soto la Marina, 500 ft., 1; 36 km. N, 10 km. W Cd. Victoria, 1 km. E El Barretal, Rio Purificacion, 1; Cd. Victoria, 1; 2 km. W Pan-American Highway (12 km. S Llera), Ejido Santa Isabel, 2000 ft., 1; Jaumave, 2400 ft., 29.
Additional records: Matamoros (Baird, 1858:506); Sierra San Carlos (El Mulato, Tamaulipeca, San Miguel) (Dice, 1937:254); Mesa de Llera (Hooper, 1953:9); Tamaulipas [state?] (Baird, 1858:506).
=Sigmodon hispidus solus= Hall
1951. _Sigmodon hispidus solus_ Hall, Univ. Kansas Publ., Mus. Nat. Hist., 5:42, October 1, type from island 88 mi. S, 10 mi. W Matamoros, Tamaulipas.
_Distribution in Tamaulipas._--Known only from two specimens from the type locality.
=Sigmodon hispidus toltecus= (Saussure)
1860. [_Hesperomys_] _toltecus_ Saussure, Revue et Mag.
Zool., Paris, ser. 2, 12:98, type from mountains of Veracruz [probably near Mirador, Dalquest, Louisiana State Univ.
Studies, Biol. Sci. Series, 1:163, December 28, 1953].
1902. _Sigmodon hispidus toltecus_, V. Bailey, Proc. Biol.
Soc. Washington, 15:110, June 2.
_Distribution in Tamaulipas._--Tropical region in southern part of state. The specimen reported by Baker (1951:216) from one mile east of El Barretal is here referred to _S. h.
berlandieri_.
_Records of occurrence._--Specimens examined, 69: Sierra de Tamaulipas, 10 mi. W, 2 mi. S Piedra, 1200 ft., 24; Sierra de Tamaulipas, 11 mi. W, 8 mi. S Piedra, 2000 ft., 1; Rancho Pano Ayuctle, 25 mi. N El Mante, 3 km. W highway, 300 ft., 3; Rancho Pano Ayuctle, 6 mi. N Gomez Farias, 300 ft., 3; 8 km. W, 10 km. N El Encino, 400 ft., 2; 2 km. W El Carrizo, 2100 ft., 20; 6 mi. N, 6 mi. W Altamira, 8; 6 mi. N, 4 mi. W Altamira, 1; 5 mi. N, 5 mi. W Altamira, 3; 1 mi. S Altamira, 1; 16 km. N Tampico, 3.
Additional records: Rancho del Cielo, 15 to 20 mi. S Mesa de Llera (Hooper, 1953:9); Cd. Mante (Ingles, 1959:398); Tampico (Booth, 1957:15).
=Neotoma albigula subsolana= Alvarez
White-throated Woodrat
1962. _Neotoma albigula subsolana_ Alvarez, Univ. Kansas Publ. Mus. Nat. Hist., 14:141, April 30, type from Miquihuana, 6400 ft., Tamaulipas.
_Distribution in Tamaulipas._--Western side of Sierra Madre Oriental.
At Nicolas specimens were taken in traps set along a thorn fence and at Tajada two specimens were trapped along a rock wall. At other places some specimens were brought in by natives who captured the rats by tearing apart their houses.
Five females taken on October 18 at Nicolas carried embryos (one to two per female), which averaged 22.2 (11-45) mm. in crown-rump length.
Another female, taken nine miles southwest of Tula on October 13, carried 2 embryos that were 35 mm. in crown-rump length. The average weight of the five pregnant females was 196.7 (183-207) grams. The average weights of nine adult males and six non-pregnant females from Miquihuana were, respectively, 215.6 (175-250) and 162.5 (155-175) grams.
_Records of occurrence._--Specimens examined, 51: Miquihuana, 6400 ft., 22; Joya Verde, 35 km. SW Cd. Victoria (on Jaumave Road) 3800 ft., 2; Nicolas, 56 km. NW Tula, 5500 ft., 10; Tajada, 23 mi. NW Tula, 5200 ft, 2; 9 mi. SW Tula, 3900 ft., 15.
Additional record: Jaumave (Goldman, 1910:37).
=Neotoma angustapalata= Baker
Tamaulipas Wood Rat