MAMMALS OP THK MEXICAN BOUNDARY. 171 



tail rather long; hoofs rathei' elougato. Skull with the vomer divid- 

 ing the posterior iiares into (wo distiiict chambers. Lachrymal 

 vacuity very large, and lachrymal fossa small. Auditory bnlhr 

 slightly inflated. Dentition.— T gE^; ^mEi; Pm 1^1; M ^Z|=;i->. Ver- 

 tebras : C 7, D 13, L 6, S 4, Ca (about) 13. Tail long or short. Color 

 uniform in adult. 



KEY TO THE MEXICAN BOUNDARY FORMS OF ODOCOILE0S. 



0. Size large ; lachrymal fossa deep, forming a pit ; horns dichotomous ; meta 



tarsal gland elongate; tail composed of about 9 short vertebra;, nalced at 



base below. 



h. Tail short, compressed at base and expanded into a heavy terminal brush, 



nalved below for more than half its length ; metatarsal gland greatly 



elongated. 



c. Upper side of tail with a median black stripe ; color dark and very red in 



summer . Odocoileus hemionns caVifornicvs (p. 211). 



cc. Tipper side of tail all white at middle; color pale and less red in summer. 

 <1. Size large ; color pale ; beam of horn long and stout, and liorns very 



divergent Odocoileus hemionns eremicns (p. 208). 



dd. Smaller ; color darker ; horns less stout, more erect, and branched, 



and with a shorter beam Odocoileus tiemioriiis caniis (p. 191). 



&7). Tail longer, flattened and tapering throughout, black above, white below, 

 naked only at extreme base ; metatarsal gland much shorter. 



Odocoileus croolci (p. 185). 

 aa. Size smaller; lachrymal fossa shallow, not forming a pit; horns not dicho- 

 tomous ; metatarsal gland extremely short ; tail of about 11 elongated ver- 

 tebrie, hairy to base below. 



c. Larger, adult male measuring 1,58.5 mm. in total length ; color mod- 

 erately pale ; ears shorter, measuring 160 mm. from crown, with 

 black edges and tips ; dentition hes.v^ -Odocoileus texanns (p. 171), 

 ee. Smaller ; total length averaging 1,454 mm. in five adult males ; 

 color extremely pale ; ears longer, averaging 192 mm. from crown, 

 without black edges and tips ; dentition weaker. 



Odocoileus foiiesi (p. 175). 



ODOCOILEUS TEXANUS (Mearns).n 

 TEXAS WHITE-TAILED DEER. 



Dorcelaphus texanus Mearns, Proc. Biol.' Soc. Wash., XII, 1898, p. 2.^, 

 January 27, 1898 (original description). 



Odocoileus tcrnnni, Thompson, Forest and Stream, LI, 1,^98, p. 280, Octo- 

 ber 8, 1898. 



Odocoileus lexcusis. Miller and Reh-n, Proc. Bost. Soc. Nat. Hist., XXX, 

 No. 1, 1901, p. 17 (Syst. Results Study N. Am. Mam. to close of 1900). 



[Odocoileus americanus] texensis, Elliot, Field Col. Mus., Zool. Ser., It, 

 1901, p. 40 (Synop. Mam. N. Am.). 



[Odocoileus americauus] tceeiisis. Elliot. Field Col. Mus., Zool. Ser.. IV, 

 Pt. 1, 1904, p. 70, pis. XXXIX, XXX (Mam. Mid. Am.). 



aAn illustration (flg. 9), showing a skull and audital region of Odocoileus 

 amcric.atius, is introduced for iiurposes of compari.son. 



