August, 1910. Mamas rrom South America—OscGoop. 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 thetip; 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 
bullz 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 O. 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 vertebra 105; hind foot 293; ear 
from notch 110. Skull of type and of an adult male O. gymnotis, 
respectively: Greatest length 218, 261; basilar length 191, 230; 
tip of premaxille to end of palate 136, 162; zygomatic width go, 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. 
E 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 tome. 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 
