August, 1910. MAMMALS FROM SOUTH AMERICA OSGOOD. 25 



and thence to the white of the chin; a prominent blackish spot on 

 each side of the chin with an irregular line of buffy between ; outside 

 of ears naked medially, grizzled buffy at the base and more blackish 

 along the anterior edge, inside broadly white at the base and rather 

 heavily clothed with white toward the tip; underparts broadly brown- 

 ish buff on the breast and for a short distance posteriorly on middle of 

 abdomen, the middle part forming a distinct dark line; abdomen, 

 inguinal region, and inner sides of hind legs nearly to hock, white; 

 inner sides of forelegs white to the elbow joint, this white being un- 

 connected with that of the abdomen; front side and lower half of 

 legs nearly clear buffy ochraceous, somewhat paler posteriorly; tail 

 ochraceous above, white below. 



Skull and teeth decidedly smaller than in O. gymnotis; audital 

 bullae smaller and more rounded; frontals very abruptly elevated and 

 strongly ridged medially; occipital condyle lower than the palatal 

 plane; antorbital vacuities relatively small; frontals deeply in- 

 dented between the base of the horn pedicel and the orbit; upper 

 molariform teeth slightly smaller than in 0. gymnotis; lower molar 

 teeth also somewhat smaller, but first and second lower premolars 

 actually and relatively larger; posterior lobe of last lower molar 

 reduced to a slender column. Antlers small and rugose except at 

 points, consisting of a single branch with a slight fork at the tip and a 

 stout upright subbasal snag. 



Measurements. Type (dressed skin, measured dry) : Total length 

 1,415; head and body 1,310; tail vertebrae 105; hind foot 293; ear 

 from notch no. Skull of type and of an adult male O. gymnotis, 

 respectively: Greatest length 218, 261; basilar length 191, 230; 

 tip of premaxillae to end of palate 136, 162 ; zygomatic width 90, 107 ; 

 mastoid width 70.8, 83.7; interorbital width 52, 63; median length 

 of nasals 59.5, 79; greatest width of nasals 27.4, 30; width between 

 outer sides of second upper molars 62.9, 73.5 ; length of upper molari- 

 form series (crowns) 64.5, 71.2; length of first and second lower pre- 

 molars 20, 18.4. 



Remarks. Externally there is little except its smaller size to distin- 

 guish this insular species from its mainland relative O. gymnotis. 

 Its skull, however, differs markedly from that of gymnotis not only 

 in size but also in many detailed characters, while in its abruptly 

 elevated braincase it differs from any deer known to me. The type 

 and only specimen was secured and presented by Mr. C. Freeman of 

 Puerto Viejo in generous response to the suggestion of Mr. Ferry, who 

 was greatly assisted by Mr. Freeman during his work on Margarita 



