Vol. 5] Merriam. — Strepsicerine Antelopes from Nevada. :i'2\ 



The type specimen (figs.l and 4) consists of the basal portion 

 of a left horn, with a part of the frontal forming the superior 

 portion of the orbit and the brain case. 



The frontal region, exclusive of the horn cores, so far as 

 represented on any of the specimens, is almost flat anterior to 

 the base of the horns (fig. 3), and the space between the horns 

 is perfectly even, or without a median ridge. Behind a line 



Fig. 1. — Ilingoceros alexandrae. Posterior view of base of left horn 

 core; a, spiral ridge arising over the postero-superior region of the orbit; 

 Is, cross-section of horn core. No. 11880, type specimen, natural size. 



Fig. 2. — Ilingoceros, form B. Posterior to postero-median view of basal 

 portion of right horn core; a, anterior spiral ridge probably corresponding 

 to ridge a in figure 1; b, median or lateral spiral ridge; c, posterior spiral 

 ridge; 0s, cross-section of horn core. No. 11892, natural size. 



