The northernmost localities from which _S. d. negligens_ has been reported are nine and a half miles southwest of Padilla in the east, and Rancho Santa Rosa in the west.

Three males from the vicinity of Padilla weighed 309, 276, and 261 grams.

_Records of occurrence._--Specimens examined, 92: 9-1/2 mi.

SW Padilla, 800 ft., 3; Rancho Santa Rosa, 25 km. N, 13 km.

W Cd. Victoria, 260 m., 8; 3 mi. NE Guemes, 1; Sierra de Tamaulipas, 10 mi. W, 2 mi. S Piedra, 1200 ft., 3; Ejido Santa Isabel, 2 km. W Pan-American Highway, 2000 ft., 20; 70 km. (by highway) S Cd. Victoria and 6 mi. W Pan-American Highway, 43; 2 km. W El Carrizo, 12; 8 km. W, 10 km. N El Encino, 400 ft., 2.

Additional records: Victoria (Nelson, 1898:147); Santa Maria (Goodwin, 1954:8); Rancho Viejo (_ibid._); Rancho del Cielo (_ibid._); 3 mi. NW Acuna (Hooper, 1953:4); Pano Ayuctle (_ibid._); Gomez Farias (Goodwin, 1954:8); Mesa de Llera, 10 mi. NE Zamorina (Hooper, 1953:4); Altamira (Nelson, 1898:147).

=Sciurus alleni= Nelson

Allen's Squirrel

1898. _Sciurus alleni_ Nelson, Proc. Biol. Soc. Washington, 12:147, June 3, type from Monterrey, Nuevo Leon.

_Distribution in Tamaulipas._--Along Sierra Madre Oriental in southwestern part of state.

This squirrel occurs in stands of oak and "nogalillos" (hickory) trees that grow along streams and arroyos. Individuals are active from sunrise to about 10:00 a. m. and again late in the afternoon. They give a soft "chirring" call.

Nelson (1899:92) noted that specimens from Miquihuana were smaller than those from the type locality. Among specimens I have examined, some are as large as topotypes and two females are larger (total length, 486 and 490) than measurements given for the species by Nelson (_op. cit._).

_Record of occurrence._--Specimens examined, 11, from Joya Verde, 35 km. SW Cd. Victoria, 3800 ft.

Additional records: Near Victoria (Nelson, 1899:92); Miquihuana (_ibid._); Joya de Salas (Goodwin, 1954:8).

=Glaucomys volans herrera.n.u.s= Goldman

Southern Flying Squirrel

1936. _Glaucomys volans herrera.n.u.s_ Goldman, Jour.

Washington Acad. Sci., 26:463, November 15, type from Mts.

of Veracruz.

_Distribution in Tamaulipas._--Known only from Aserradero del Infernillo (Goodwin, 1954:9 and 1961:9).

=Geomys personatus personatus= True

Texas Pocket Gopher

1889. _Geomys personatus_ True, Proc. U. S. Nat. Mus., 11:159 for 1888, January 5, type from Padre Island, Cameron County, Texas.

_Distribution in Tamaulipas._--Known only from the barrier beach in northeastern part of state.

The specimens examined are referred, tentatively, to _Geomys personatus personatus_ on geographic grounds. They average smaller in all measurements than _personatus_ (but are larger than _G. p.

megapotamus_), do not have the sagittal crest that usually is present in _personatus_, and the shape of the pterygoid bones is distinctive.

In _personatus_ and _megapotamus_ the ventral border of the pterygoids (in lateral view) is convex instead of nearly straight as in specimens from the barrier beach. The specimens recorded here are all that are known of _G. personatus_ (see account of _G. tropicalis_) from Mexico.

_Measurements._--Average and extreme external measurements of five females from 73 miles south of Washington Beach are as follows: 266.8 (263-271); 94.8 (91-98); 34 (33-35).

Cranial measurements of two males (89038, 89032) and average and extremes of five females are respectively: basal length, 49.1, 46.6, 45.9 (44.2-46.8); basilar length, 42.9, 40.0, 39.8 (38.0-40.8); zygomatic breadth, 29.6, 28.3, 28.0 (25.7-29.9); squamosal breadth, 27.8, 25.9, 26.2 (23.8-25.4); interorbital constriction, 7.4, 6.9, 7.3 (6.7-7.8); alveolar length of maxillary tooth-row, 10.3, 9.2, 9.4 (9.1-9.7).

_Records of occurrence._--Specimens examined, 17: 35 mi. SSE Matamoros, 8; 33 mi. S Washington Beach, 1; 73 mi. S Washington Beach, 8.

Additional record: 4 mi. S Washington Beach (Selander _et al._, 1962:335--possibly fragmentary skeletal remains never catalogued in any research collection).

=Geomys tropicalis= Goldman

Tropical Pocket Gopher

1915. _Geomys personatus tropicalis_ Goldman, Proc. Biol.

Soc. Washington, 28:134, June 29, type from Altamira, Tamaulipas.

_Distribution in Tamaulipas._--Known only from vicinity of type locality, in southeastern part of state.

_Geomys tropicalis_ was named as a subspecies of _G. personatus_ in 1915 by E. A. Goldman. To my knowledge, no one other than Goldman has critically studied specimens of this pocket gopher, nor have specimens other than those listed in the original description been reported up to now. In 1953, Gerd H. Heinrich collected a series of 19 individuals one mile south of Altamira. These specimens were compared (by E. R. Hall in March, 1962) with the holotype and paratypes of _G. p. tropicalis_ and were found to be indistinguishable.

Careful comparisons of the specimens from one mile south of Altamira with topotypes of _G. personatus personatus_ (and specimens of other subspecies) indicate that _tropicalis_ differs from _personatus_ in a number of important characters, some of which _tropicalis_ shares with _Geomys arenarius_ of the Rio Grande Valley and adjacent areas in Texas, New Mexico, and Chihuahua (see Table 2).

TABLE 2.--DIFFERENCES BETWEEN THREE SPECIES OF GEOMYS.

=========================+==============+===============+==============

_G. arenarius_

_G. personatus_

_G. tropicalis_ -------------------------+--------------+---------------+-------------- Zygomatic arches

parallel

narrower

narrower

posteriorly

posteriorly Sagittal crest

absent

present

small Squamosal k.n.o.b

present

absent

present Interparietal

subquadrant

triangular

triangular Mesopterygoid fossa

V-shaped

U-shaped

V-shaped Ratio, zygomatic breadth

to basal length

63.7-66.6

66.3-67.2

60.8-66.2 Ratio, mastoid breadth

to basal length

58.0-60.4

59.8-63.1

58.0-59.6 Border of premaxilla at

incisive foramina

wedge-shaped

subquadrate

subquadrate -------------------------+--------------+---------------+--------------

As can be seen in the accompanying table _tropicalis_ resembles _arenarius_ in half of the eight characters considered, especially in the presence of a k.n.o.b on the zygomatic process of the squamosal (the diagnostic character of _arenarius_ according to Merriam, 1895:140) and in the shape of the mesopterygoid fossa. _G. tropicalis_ differs from _arenarius_ princ.i.p.ally in having a low sagittal crest in adult males (lacking in _arenarius_) and in the shape of the interparietal bone, which in _tropicalis_ is small (in some skulls difficult to see) and triangular instead of being relatively large and subquadrate as in _arenarius_.

_G. tropicalis_ resembles _personatus_ in half of the characters considered, notably in shape of the interparietal bone, outline of zygomatic arches, and constriction of the premaxillae where they border the incisive foramina.

Considering the distinctive combination of characters possessed by _tropicalis_, and its isolated, restricted geographic range (the nearest known record of _Geomys_ is approximately 165 miles to the north), _tropicalis_ is here regarded as a full species. A skull alone examined from 10 miles northwest of Tampico does not differ from those of other specimens studied.

The average weight of five non-pregnant July-taken females was 189.4 (180-200) grams. Weights of three males were 280, 270, and 255 grams.

Females are in all measurements smaller than males.

_Measurements._--Average and extreme measurements of five females and three males from one mile south of Altamira are, respectively, as follows: 243.5 (235-250), 260, 260, 265; 82.0 (78-85), 87, 93, 89; 32.2 (31-33), 35, 35, 33; ear from notch in both s.e.xes, 5; condylobasal length, 42.3 (41.3-43.1), 46.0, 48.0, 46.2; zygomatic breadth, 26.6 (25.1-27.7), 30.4, 31.2, 30.5; interorbital constriction, 6.2 (6.1-6.3), 6.0, 6.2, 6.3; length of nasals, 14.6 (14.0-15.3), 17.0, 16.8, 15.9; alveolar length of maxillary tooth-row, 9.0 (8.6-9.3), 9.9, 10.0, 9.4.

_Records of occurrence._--Specimens examined, 19: 1 mi. S Altamira, 18; 10 mi. NW Tampico, 1.

Additional record: Altamira (Goldman, 1915:134).

=Heterogeomys hispidus negatus= Goodwin

Hispid Pocket Gopher

1953. _Heterogeomys hispidus negatus_ Goodwin, Amer. Mus.

Novit., 1620:1, May 4, type from Gomez Feras [Farias], 1300 ft., Tamaulipas.