E. L. Troxell — Fossil Ruminant from Texas. 481 



meter above the larabdoid crest. The parietal is not paired 

 but, as in many Artiodactyla, was probably fused early in life. 

 The frontal and squamosal form a deep groove on the side'of 

 the head, parallel to the suture, continuing into the orbit 

 anteriorly and ending posteriorly at the ridge which lies along 

 the side of the skull. The outer extremity of the lambdoid 

 crest continues into this sharp ridge, which marks the union 

 of the squamosal, parietal and occipital portion of the skull later- 

 ally, giving this region a flat appearance. The crest loops down- 

 ward in its middle portion to join the central tubercle which 

 formed the attachment for the nuchae ligamentum — the chord 

 which follows along the back of the neck. Two fossae are 

 observed on either side of this tubercle. They are shallow, 

 however, since the lambdoid crest does not markedly over- 

 hang the occiput. The lambdoid suture below the crest is 

 obscured. 



The skull is very deep from a point between the horns to 

 the occipital condyles and in general is very stout. The 

 anterior portion is broken off just above the orbits. A slight 

 rise in the frontals anteriorly suggests that the animal had a 

 rounded forehead. The foramen magnum for the most part 

 opens on the dorsal surface of the occiput. 



Dimensions. mm. 



Inter-cornu space — 75 



Diam. of horn cores ant. -post. 74 



" " " " transverse 85 



Breadth of forehead, anterior to horns 144 



Breadth of cranium, posterior to horns _ 92 



Depth from point between horns to extremity of 



occipital condyle 167 



Width of basi-occipital — 55 



Cranio-f acial angle, about -- 45° 



Occiput-facial angle, about - 68£° 



The specimen is placed in the genus Preptoceras because of 

 the very great general similarity to the type. It differs from 

 Preptoceras sinclairi in that its fossae just beneath the 

 lambdoid crest are not so deep ; the lambdoid suture lies near 

 this crest (this is like Euceratherium); the horns are smaller, 

 less rounded dorsally and more widely separated ; they do not 

 come out " from the extreme posterior and lateral ends of the 

 frontals " as in the type species but are situated three centi- 

 meters from the posterior and four from the lateral borders. 



The present species differs very greatly from Liops zuniensis. 

 The horns of the latter are set wide apart, 'come out straight 

 from the skull and droop decidedly ; they have no burrs on 

 the horns, no true lambdoid crest and the skull generally is 

 smooth in the extreme. 



Am. Jour. Sci.— Fourth Series, Vol. XL, No. 239.— November, 1915. 

 32 



