Part 2

In the United States National Museum in July, 1949, the specimen providing the easternmost record station of occurrence was examined by us. This is No. 23591, in alcohol, taken on August 24, 1890, by William Lloyd, original No. 88, at the mouth of the Pecos River in Texas. In the same collection there is a specimen of Pipistrellus subflavus providing the westernmost record of occurrence of that species. This specimen, a skin with skull, is No. 126729, , taken on May 3, 1903, by Jas. H. Gaut, original No. 1271, at Comstock, Texas. The two localities concerned are in the Valley of the Rio Grande, and are only about five miles apart. Nevertheless, the two specimens are clearly referable to their respective species and show no tendency toward intergradation. Consequently, confidence is felt in treating Pipistrellus hesperus and Pipistrellus subflavus as two distinct species.

The most recent report upon geographic variation throughout the entire species, Pipistrellus hesperus, was that by Hatfield (Jour. Mamm., 17:257-262, August 14, 1936). Later, as explained below in the account of P. h. australis, Burt (Miscl. Publ., Mus. Zool., Univ. Michigan, 39:25, February 15, 1938) examined specimens from Sonora, Mexico, and for them and for specimens from southern Arizona proposed a different nomenclatural arrangement.

1. Pipistrellus h. hesperus 2. Pipistrellus h. merriami 3. Pipistrellus h. australis 4. Pipistrellus h. maximus 5. Pipistrellus h. santarosae 6. Pipistrellus s. subflavus 7. Pipistrellus s. obscurus 8. Pipistrellus s. veracrucis ]

+Pipistrellus hesperus hesperus+ (H. Allen)

Scotophilus hesperus H. Allen, Smithsonian, Miscl. Coll., No. 165, Vol. 7 (art. 1): p. 43, June, 1864.

Vesperugo hesperus True, Proc. U. S. Nat. Mus., 7:602, 1885.

Pipistrellus hesperus Miller, N. Amer. Fauna, 13:88, October 16, 1897.

Type locality.--Old Fort Yuma, Imperial County, California, on right bank of Colorado River, opposite present town of Yuma, Arizona.

Range.--Intermontane region of the United States from south-central Washington south to Catavina, Baja California, and from southeastern California eastward to southeastern Utah. Marginal occurrences (unless otherwise indicated, after Hatfield, Jour. Mamm., 17:258, 1936) are: Washington (Dalquest, Univ. Kansas Publ., Mus. Nat. Hist., 2:165, 1948): Maryhill; Vantage; Almota. Oregon: Watson. Idaho: 8 mi. W Rogerson (Davis, Mamms. Idaho, p. 120, 1939). Nevada: Middle Stormy Spring (Hall, Mamms. Nevada, p. 151, 1946). Utah: Goodridge. Arizona: 11 mi. NW Kayenta; Tinajas Altas. Baja California: Catavina; San Jose; Laguna Hanson. California: Dos Palmos Spring; Banning; Victorville; 12 mi. below (down river) Bodfish; Little Lake; 2 mi. S Benton Station. Nevada: 2 mi. NW Morgans Ranch; Deephole. Oregon: Princeton.

Diagnosis.--Size medium for the species; total length, 71.8(66-74); tibia, 12.0(10.7-13.5); forearm, 29.4(27.8-31.8); greatest length of skull, 11.9(11.5-12.3); breadth of braincase, 6.3(6.1-6.4). Color between Drab Gray and Smoke Gray, dorsally; between Smoke Gray and Pale Smoke Gray, ventrally (after Hatfield, Jour. Mamm., 17:257, 1936).

+Pipistrellus hesperus merriami+ (Dobson)

Vesperugo merriami Dobson, Ann. and Mag. Nat. Hist., 18(ser. 5): 124, August, 1896.

Pipistrellus hesperus merriami Grinnell, Proc. California Acad. Sci., 3(ser. 4):279, August 28, 1913.

Type locality.--Red Bluff, Tehama County, California.

Range.--California west of the Sierra Nevada; the Sacramento Valley, the San Joaquin Valley, and the Coast Range from San Francisco Bay south to San Diego County. Marginal occurrences (after Hatfield, Jour. Mamm., 17:260, 1936, unless otherwise noted) are: California: Dales on Paines Creek; Fyffe; Yosemite Valley; Shaver Ranger Station; Springville; Fort Tejon; Painted Gorge (P. H. Krutzsch, MS); Carrizo Creek; thence northward up the coast probably to San Francisco Bay; in the Sacramento Valley west to Rumsey.

Diagnosis.--Size medium for the species; total length, 71.3(66-78); tibia, 11.2(10.6-11.7); forearm, 28.9(27.5-30.8); greatest length of skull, 11.8(11.3-12.2); breadth of braincase, 6.4(6.0-6.6). Color Buffy Brown to Army Brown, dorsally; Wood Brown to Buffy Brown, ventrally (after Hatfield, op. cit.: 258, 260).

+Pipistrellus hesperus australis+ Miller

Pipistrellus hesperus australis Miller, N. Amer. Fauna, 13:90, October 16, 1897.

Pipistrellus hesperus apus Elliot, Field Columb. Mus., pub. 90, zool. ser., 3:269, March 8, 1904. Type from Providencia Mines, Sonora, Mexico.

Type locality.--Barranca Ibarra, Jalisco, Mexico.

Range.--Central Arizona south to Jalisco and including the southern half of Baja California. Marginal occurrences (after Hatfield, op. cit.: 261, unless otherwise indicated) are: Arizona: Camp Verde; Fort Bowie. Sonora: Pilares (Burt, Miscl. Publ., Mus. Zool., Univ. Michigan, 39:24, 1938). Jalisco: Barranca Ibarra (Miller, orig. descr.). Baja California: Miraflores; San Ignacio. Arizona: Bates Well.

Diagnosis.--Size small for the species; total length, 67.1(60-72); tibia, 11.3(10.1-12.3); forearm, 28.4(26.3-30.0); greatest length of skull, 11.7(11.3-12.0); breadth of braincase, 6.1(5.9-6.3). Color: between Cinnamon Drab and Drab, dorsally; Wood Brown to Light Drab, ventrally (after Hatfield, op. cit.:260).

Remarks.--Hatfield (op. cit.) examined no specimens from Mexico (Baja California excepted) and Burt (op. cit.) who did examine some specimens (from Sonora), referred one from northwestern Sonora to P. h. hesperus and those from northeastern Sonora to P. h. merriami. Since our treatment of subspecies of Pipistrellus (P. s. veracrucis excepted) aims merely to reflect the latest systematic treatment accorded the animals, we would follow Burt (op. cit.) were it not for the fact that he shows the geographic range of P. h. merriami separated by the range of P. h. hesperus into two parts. This is inconsistent with the ordinarily accepted concept of subspecies. Consequently, we have followed Hatfield (op. cit.). Clearly, a critical study is needed of adequate material of Pipistrellus hesperus of Mexico.

+Pipistrellus hesperus maximus+ Hatfield

Pipistrellus hesperus maximus Hatfield, Jour. Mamm., 17:261, August 14, 1936.

Type locality.--Dog Spring, Hidalgo County, New Mexico.

Range.--Southern New Mexico, western Texas and probably the adjoining parts of Mexico. Marginal occurrences (after Hatfield [op. cit.:261] except as otherwise indicated) are: New Mexico: Animas Valley; Florida Mountains; Carlsbad Cave. Texas: Mouth of Pecos River (Bailey, N. Amer. Fauna, 25:210, 1905); Boquillas (Borell and Bryant, Univ. California Publ. Zool., 48:9, 1942); Glen Spring (Borell and Bryant, loc. cit.).

Diagnosis.--Size large for the species; total length, 80.3(78-83); tibia, 12.3(11.7-13.1); forearm, 32.9(31.8-33.3); greatest length of skull, 12.7(12.3-12.9); breadth of braincase, 6.6(6.5-6.7). Color between Smoke Gray and Pale Drab (after Hatfield, op. cit.:261).