246 WASATCH FAUNA. 



at the symphysis than at the hist iiKtlar. What appears to be the dental 

 foramen is nearly opi>osite the bases of the crowns of the molars. 



Dentition of the ramus mandibuli, In. 2, C. 1, Pm. 2, M. 3; total 16. 

 There is no interruption in the series near the canine, and the symphysis, 

 though massive, is not coossified. The third (first) premolar is two-rooted. 

 Further details are, tlie last mohir is three-lobed and elongated behind. 

 The composition of the crowns of the preceding molars consists of four 

 opposed lobes, which are very stout, and connected transversely by a thin 

 ridge behind, and are in close contact in front. The premolar tooth, which 

 is best preserved, is a perfect second, which, while having two roots, pos- 

 sesses a crown which stands almost entirely on the anterior, presenting a 

 curved sectorial crest forwards and upwards. 



• The orbits are large and are entirely inclosed behind. The frontal 

 bone does not send inwards to the alisphenoid a lamina to separate the orbit 

 from the temporal fossa, as is seen in Tarsius. There is no sagittal crest, 

 but the temporal ridges are distinct. The occipital region protrudes beyond 

 the foramen magnum, or at least beyond the paroccipital process, wliich is 

 preserved, the condyles being lost. The otic bulla is large, extending 

 anteriorly to the glenoid cavity. The pterygoid fossa is large, the external 

 pterygoid ala being well developed, and extending well upon the e.xtero- 

 anterior side of the bulla, as in Tarsius. As in that genus, the foramen 

 ovale is .situated on the external side of the bulla, just above the base of 

 the extenial pterygoid ala. Tho carotid foramen, as I suppose it to be, is 

 situated at the apex of tiie bulla. The lachrymal foramen is situated ante- 

 rior to and outside of the orbit, as in Lemuridce generally. 



The cast of the anterior part of the left cerebral hemisphere is exposed. 

 This projects as far anteriorly as the middle of the orbits, leaving but little 

 room for the olfactory lobes. The relations of the latter, as well as of other 

 parts of the brain, will be examined at a future time. The part exposed 

 does not display fissures, and gentle undulations represent convolutions. 



The characters of this genus now known warrant us in thinking it one 

 of the most interesting of Eocene Mammalia. Two special characters con- 

 firm the reference to tho Lemuruhr which its ])hvsiognomv suggests. These 



