MAMMALS OF THE MEXICAN BOUNDARY. 171 



tail rather long; lioofs rather elongate. Skull with the vomer divid- 

 ing the posterior nares into two distinct chambers. Lachrymal 

 vacuity very large, and lachrymal fossa small. Auditory bulla 1 

 slightly inflated. Dentition. [§ §; C ',' ',': Pm | g; Mg IJ=:32. Ver- 

 tebraj: C7,DI3,L6,S I. Cm (about) 13. Tail long or short. Color 

 uniform in adult. 



KEY. TO THE MEXICAN BOUNDARY FORMS 01 ODOCOILEUS. 



a Size large; lachrymal fossa deep, forming a pit; horns clichotomous ; i;i 



tarsal gland elongate; tail composed of about '.» short vertebra?, naked at 



base below. 



//. Tail short, compressed at base and expanded into a beavy terminal brush, 



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



elongated. 



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



summer Odocoileus liemionus californicus (p. 211). 



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

 il. Size large; color pale; beam of horn long and stout, and horns very 



divergent Odocoileus liemionus eremicus (p. 208). 



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



and with a shorter beam Odocoileus liemionus can us (p. 191 I. 



bh. Tail longer, flattened and tapering throughout, black above, wb'ite below, 

 naked only at extreme base; metatarsal eland much shorter. 



Odocoileus croolci (p. 185). 

 aa. Size smaller: lachrymal fossa shallow, not forming a pit: horns not dicbo- 

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

 tebrae, hairy to haso below. 



c. Larger, adult male measuring 1,585 mm. in total length; color mod- 

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

 black edges and tips: dentition heavy Odocoileus texanus (p. 171 I. 

 re. Smaller; total length averaging 1,454 mm. in live adult males; 

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

 without black edges and lips: dentition weaker. 



Odocoileus couesi (p. 175). 



ODOCOILEUS TEXANUS ( M earns ,." 

 TEXAS WHITE-TAILED DEER. 



Dorcelaphus texanus Mearns, Proc. Biol. Soc. Wash.. XII. 1808, p. 23, 

 January 27. 1898 (original description!. 



Odocoileus texanus, Thompson, Foresl and Stream, Id. 1898, p. 280, Octo- 

 ber 8, 1898. 



Odocoileus texensis, Miller and Rehn, Proc. Bost. Soc Nat. Hist.. XXX. 

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



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

 1901, p. 4ii (Synop. Mam. X. Am.). 



[Odocoileus americanus] te.ren.six. Elliot, Field Col. Mus.. Zool. Ser., iv. 

 Pt. 1. 1904, p. 70. pis. \wi\. xxx i Mam. Mid. Am.). 



"An illustration (fig. '•>!. showing a skull and audital region of Odocoileus 

 americanus, is introduced for purposes of comparison. 



