ODONTOCGELUS. 69 



KEY TO THE SPECIES AND SUBSPECIES. 



A. Size small. 



a. Horns similar in shape to those of O. americanus. PAGE 

 a/ Upper parts pale reddish; tail above black. O. a. texensis 70 

 b/ Upper parts dull fawn; tail reddish brown. . .O. a. couesi 70 

 c/ Upper parts gray brown ; tail grizzled white 



and brown O. battyi 7 1 



d/ Upper parts speckled foxy red ; tail foxy red 



O. lichtensteini 7 2 



e/ Upper parts brown, tipped with fawn; 



tail fawn, tip black O. rothschildi 7 2 



b. Horns slightly lyrate, beams straight, 

 a/ Tarsal gland present. 



a." Upper parts bright chestnut ; tail above 



tawny O. truii 73 



b/' Upper parts mixed black and buff; tail 



above cinnamon O. costaricensis 73 



c." Upper parts yellowish brown and gray; 



tail above dusky O. nemoralis 74 



b/ Tarsal gland absent. 



a/' Upper parts dark chestnut brown ; tail 



above brown O. toltecus 74 



c. Horns sloping back on plane of face, tips 

 curving inward and forward, with a spike 

 from burr on inner side curving inward 



and forward O. thomasi 75 



d. Horns small subcylindrical spikes O. nelsoni 75 



B. Size large. 



a. Horns with a single branch from main tine. .O. cerrosensis 76 



b. Horns with short sub-basal snag, and beam 

 curving upward and forming a dichotomous 

 fork and again dividing, the normal points 

 being five on a side. 



a/* Upper parts tawny ; tail white with black 



tip O. hemionus 76 



b/* Upper parts pale tawny; tail with dark 



median band above, tip black O. h. californicus 77 



c.'* Upper parts fulvous; tail whitish, tip 



black O. h. eremicus 77 



d/* Upper parts drab gray; tail, basal half 



dark, middle part white, tip black O. h. can us 78 



* Summer pelage described. 



