Part 19

United States National Museum (Biol. Surv. Collections).

American Museum of Natural History.

Univ. Illinois, Mus. Nat. History.

The Museum, Michigan State Univ.

Univ. Michigan, Museum of Zoology.

=Baiomys taylori subater= (V. Bailey)

Peromyscus taylori subater, V. Bailey, N. Amer. Fauna, 25:102, October 24, 1905; Lyon and Osgood, Bull. U. S. Nat. Mus., 62:139, January 15, 1909; Osgood, N. Amer. Fauna, 28:255, April 17, 1909; Elliot, Check-List Mamm. N. Amer. Continent, West Indies and Neighboring Seas, Suppl., Amer. Mus. Nat. Hist, p. 44, January 8, 1917.

Baiomys taylori subater, Miller, Bull. U. S. Nat. Mus., 79:136, December 31, 1912; Miller, Bull. U. S. Nat. Mus., 128:317, April 29, 1924; Anthony, Field Book of North American Mammals, p. 348, 1928; Baker, Jour. Mamm., 21:223, May 14, 1940; Ellerman, The Families and Genera of Living Rodents, 2:402, March 21, 1941; Blair, Jour. Mamm., 22:378, November 14, 1941; Poole and Schantz, Bull. U. S. Nat. Mus., 178:259, March 6, 1942; Blair, Jour. Mamm., 23:196, May 14, 1942; Blair and Blossom, Contrib. Lab. Vert. Biol., Univ. Michigan, 40:1, March, 1948; Miller and Kellogg, Bull. U. S. Nat. Mus., 205:511, March 3, 1955; Hall and Kelson, The Mammals of North America, 2:659, March 31, 1959.

Baiomys taylori [= subater], Taylor and Davis, Texas Game, Fish and Oyster Comm. Bull., 27:56, August, 1947 (part).

Type.--Subadult female, skin and skull; No. 32616/44539 U. S. Nat. Mus. (Biol. Surv. Coll.); Bernard Creek, near Columbia, Brazoria County, Texas; obtained on February 25, 1892, by W. Lloyd, original number 1122.

Range.--Southeastern Texas, north of Matagorda Bay west to Lavaca County, north to Brazos and Walker counties thence east to Jefferson County, see Figure 11. Occurs from near sea level in Brazoria and Galveston counties, up to 500 feet in western part of range. Zonal range: Humid division of lower Austral (the western part of the Austroriparian Biotic Province of Dice, 1943:18-21).

Diagnosis.--Size medium to large for the species; mid-dorsal region Clove Brown (sooty in freshly captured specimens); some parts of mid-dorsal region all blackish; individual guard hairs of dorsum black-tipped, Deep Neutral Gray basally; underfur black-tipped with subterminal band of light buff, Neutral Gray at base; belly grayish-white, laterally Isabella Color; distal three-fourths of hairs in region of throat and chin white, proximal fourth light gray; in median region of belly distal half of individual hairs white, proximal half dark gray; vibrissae in most specimens black to base. Average and extreme cranial measurements of six adults from 7 mi. S La Belle are as follows: occipitonasal length, 18.9 (17.5-19.4); zygomatic breadth, 9.6 (9.1-9.9); postpalatal length, 6.8 (6.2-7.2); least interorbital breadth, 3.7 (3.4-3.9); length of incisive foramina, 4.0 (3.6-4.2); length of rostrum, 6.5 (6.1-6.8); breadth of braincase, 8.7 (8.3-8.9); depth of cranium, 6.7 (6.6-6.8); alveolar length of maxillary tooth-row, 3.1 (2.9-3.2). Average and extreme external measurements of four adults from Richmond are as follows: total length, 111.5 (108-118); length of tail vertebrae, 43.5 (41-47); length of body, 68 (67-71); length of hind foot, 14 (13-15); for photographs of the skull, see Plate 2f, and Plate 4g.

Comparisons.--Because B. t. subater intergrades only with B. t. taylori to the south and west, subater is compared only with taylori. Young adults of both subspecies in unworn pelage show best the colors that differentiate the two subspecies. Old adults of subater in worn pelage appear grayish, resembling taylori, and at that age, only certain cranial characters are of taxonomic use. Cranially, subater differs from taylori in: presphenoid not shaped like an hour-glass; parapterygoid processes thicker medially; interparietal diamond-shaped instead of elongated and compressed. Skull slightly larger in most measurements.

Photographs of skulls in dorsal view of Baiomys. x 2.

a. B. m. brunneus, ad., 10834, AMNH, Jalapa, Veracruz. b. B. m. grisescens, ad., 257080, USNM, Comayabuela, Honduras. c. B. m. handleyi, ad., 275597, USNM, Sacapulas, Guatemala. d. B. m. infernatis, ad., 91499, MZUM, Teotitlan, Oaxaca. e. B. m. musculus, ad., 45462, USNM, Colima, Colima. f. B. m. nigrescens, ad., 76834, USNM, Comitan, Chiapas. g. B. m. pallidus, ad., 4802, Texas A & M, Axochiapan, Morelos. h. B. m. pullus, ad., 71608, KU, 8 mi. S Condega, Nicaragua. i. B. t. allex, ad., 45453, USNM, Colima, Colima.]

Photographs of skulls (a-g) in dorsal view of Baiomys. x 2.

a. B. t. analogous, ad., 120265, USNM, Zamora, Michoacan. b. B. t. ater, ad., 15056, UI, 1-1/2 mi. ENE Greaterville, Arizona. c. B. t. canutus, ad., 62076, KU, 1 mi. S Pericos, Sinaloa. d. B. t. fuliginatus, ad., 36771, KU, type locality. e. B. t. paulus, ad., 40032, KU, 18 mi. W, 2 mi. S Aguascalientes. f. B. t. subater, ad., 44543, USNM, type locality. g. B. t. taylori, ad., 57944, KU, 5 mi. E San Antonio, Texas. h. Photo. of captive B. t. taylori, 25 mi. E Austin, Texas. x 1.]

Photographs of skulls in ventral view of Baiomys. x 2.

a. B. m. brunneus, ad., 10834, AMNH, Jalapa, Veracruz. b. B. m. grisescens, ad., 257080, USNM, Comayabuela, Honduras. c. B. m. handleyi, ad., 275597, USNM, Sacapulas, Guatemala. d. B. m. infernatis, ad., 91499, MZUM, Teotitlan, Oaxaca. e. B. m. musculus, ad., 45462, USNM, Colima, Colima. f. B. m. nigrescens, ad., 76834, USNM, Comitan, Chiapas. g. B. m. pallidus, ad., 4802, Texas A & M, Axochiapan, Morelos. h. B. m. pullus, ad., 71608, KU, 8 mi. S Condega, Nicaragua.]

Photographs of skulls in ventral view of Baiomys. x 2.

a. B. t. allex, ad., 45453, USNM, Colima, Colima. b. B. t. analogous, ad., 120265, USNM, Zamora, Michoacan. c. B. t. ater, ad., 15056, UI, 1 mi. ENE Greaterville, Arizona. d. B. t. canutus, ad., 62076, KU, 1 mi. S Pericos, Sinaloa e. B. t. fuliginatus, ad., 36771, KU, type locality. f. B. t. paulus, ad., 40032, KU, 18 mi. W, 2 mi. S Aguascalientes. g. B. t. subater, ad., 44543, USNM, type locality. h. B. t. taylori, ad., 57944, KU, 5 mi. E San Antonio, Texas.]

Remarks.--This subspecies retains its chief diagnostic character, blackish mid-dorsal region, throughout nearly all parts of its range. Specimens from the general area of Matagorda Bay and Lavaca County grade into taylori in characters of color and crania. The Colorado and Brazos rivers seemingly serve as barriers reducing gene flow between taylori and subater. These rivers may well have been important factors in the origin and the limitation of these two seemingly closely-related subspecies.

Baiomys taylori subater is not differentiated in color of pelage and characters of crania from B. t. taylori to the same degree that B. t. paulus is differentiated from B. t. analogous, or that B. t. taylori is differentiated from several of the other subspecies of Baiomys taylori. B. t. subater probably is a more recent occupant of the area in which it now lives than is the case with any other one of the subspecies of taylori. Sufficient time probably has not elapsed to allow for formation of more distinctive phenotypic patterns.

Specimens examined.--Total 65, all from TEXAS and distributed as follows: Brazos County: 1/2 mi. NW College Station, 1; 3 mi. W College Station, 1 mi. W Easterwood Airport, 1; College Station, 1. Walker County: Huntsville, 1. Hardin County: Sour Lake, 1. Jefferson County: 7 mi. S Labelle, 10. Harris County: 6 mi. NE Crosby, 1. Colorado County: 10 mi. N Eagle Lake, 1; 9 mi. N Eagle Lake, 1; 2 mi. W Eagle Lake, 1; Eagle Lake, 1, 5. Fort Bend County: Richmond, 4. Galveston County: Texas City, 6; Virginia Point, 1. Brazoria County: Austin Bayou near Alvin, 2; 14 mi. SSE Alvin, 2; type locality, 7 (including the type). Lavaca County: 4 mi. W Hallettsville, 1; 1 mi. SW Hallettsville, 3; 13.7 mi. SW Hallettsville, 2; 4 mi. NE Yoakum, 11.

Marginal records.--TEXAS: Huntsville; Sour Lake; 7 mi. S La Belle; Virginia Point; 14 mi. SSE Alvin; type locality; 4 mi. NE Yoakum; 4 mi. W Hallettsville; 1/2 mi. NW College Station.

Texas A & M, Cooperative Wildlife Research Collection.

Carnegie Museum.

U. S. Nat. Museum (Biol. Surv. Coll.).