MAMMALS OF THE MEXICAN BOUNDARY. 381 



Genus BAIOMYS True (1894). 



Baiomys Tbue, Proc. U, S. Nat. Mug., XVI, p. 758, Feb. 4, 1894. 



Ascending ramus of mandible short and erect. Condyle terminal. 

 Coronoid process well developed, uncinate, and near the condyle. 

 Size very small, tail short. Plantar tubercles, six. Soles (fig. 67) 

 hairy (True). 



Fig. 67. — Baiomys taylori. Under surface of feet, u,, forefoot; b, hindfoot. 



Type. — Hesperomys ( Vesperimus) taylori Thomas, from San Diego, 

 Texas. 



BAIOMYS TAYLORI (Thomas). 

 TAYIOR MOUSE. 



Hesperomys (Vesperimus) taylori Thomas, Ann. and Mag. Nat. Hist.; 5th ser., XIX, 



1887, p. 66 (original description). 

 Cricetus (Vesperirmbs) taylori, Thomas, Proc. Zool. Soc. Lond., 1888, p. 446. 

 Sitomys^Baiomys) taylori, Tbue, Proc.'U. S. Nat. Mus., XVI, 1894, pp. 7-57, 758.— 



Allen, Bull. Am. Mus. Nat. Hist., VI, p. 181, May 31, 1894. 

 Peromyscus (Baiomys) taylori, Allen, Bull. Am. Mus. Nat. Hist., VIII, pp. 65, 66. 



Type-locality. — San Diego, southern Texas. (Type in the British 

 Museum.) 



Geographicalrange. — Tamaulipan Tropical Tract (Rockport, Browns- 

 ville, San Diego, and 15 miles south of San Antonio, Texas). 



Fig. 68.— Baiomys taylori. Crowns of molar teeth, showing progressive stages of wear. 

 u, t, and e, lower, 6, d, and /, upper series. 



Description. — One of the smallest known North Antierican mice. 

 In no wise closely related to any other described species from the 

 United States, but closely related to Sitomys musculus Merriam 

 {= Baiomys musculus) , hom. near Colinia City, Mexico." Length of 



a Described in Proceedings of the Biological Society of Washington, VIII, pp. 170, 171, 

 September 29, 1892. 



