20 



E. M. MUSEUM MEMOIRS. 



grotesque appearance, which must have been heightened, if, according to the 

 questionable theory, they bore horns. The Loxolophodon protuberances are 

 of more modest proportions, but still out of keeping with anything at present 

 found in nature. In side view the Uintatheriutn canines are seen to project 

 more backwards, and the premaxillaries are shorter. It is at once noticed 

 that the eye of this genus must have appeared smaller and more sunken from 

 the excessively developed supraorbital ridges. The condyles of Loxolophodon 

 are more closely attached ; the occiput overhangs them slightly in both genera. 

 The malar and jugal portions of the zygoma unite by suture in Loxolophodon, 

 by smooth articular facets in the allied genus. Many of these minor characters 

 are undoubtedly due to variations which would not extend through all the species. 

 At the base of the skull we find characters which seem to be more permanent. 

 The premaxillaries send in a very narrow strip to form the anterior portion of 

 the hard palate in Uintatherium. The foramen incisivum is unenclosed, but 

 towards the extremity of the tips two small processes, partly broken in our 

 specimen, show that in the living state this foramen was partly enclosed. In 

 Loxolophodon broad plates grow well forwards on the inner sides of the pre- 

 maxillaries, extending the hard palate much further forwards. It is extended 

 further back also, in L. cornutus to a point slightly behind the last molar. In 

 U. Leidianmn the horizontal palatine and maxillary plates are somewhat shorter, 

 and the posterior nares open opposite the penultimate molar. 



LOXOLOPHODON SPEIRIANUM, sp. nov. 



General Features of the Skull. The skull is long and narrow, with a high 

 occiput, surmounted by a slight ridge. The median protuberances project well 

 outwards, and are placed considerably anterior to the orbits. In front of them 

 the nasals narrow gradually into the snout. The zygoma arches well outwards. 

 The upper surface of the skull between the frontal and occipital protuberances 

 is gently rounded upwards — although the upper outline is somewhat exaggerated 

 in our specimen from lateral crushing. When compared with other species the 

 features just detailed come out very prominently ; in fact, this skull breaks down 

 many of the characters which have hitherto been assigned as distinguishing the 

 whole genus. 



Comparison with L. cornutus. The median protuberances in L. Speirianum 

 are smaller, and their forward position relatively shortens the snout, and gives 

 greater distance between them and the posterior protuberances. The total 

 length of the skull is the same in both species. The nasals are not cleft in 

 front, and the knobs, misnamed protuberances, which they bear, project more 

 upwards. The zygomatic arches are closer to the skull in L. cornutus, the 



