510 GEOLOGICAL SUEVEY OF THE TERRITORIES. 



two acate lobes, the third as high as the anterior, while the fourth nearly 

 reaches the line of the base of the anterior notch. There is no anterior 

 basal lobe. The sectorial was of large size, judging by the alveolus. 

 The first premolar was also large and two-rooted. The alveolus for the 

 inferior canine is flat on the inner side. The increasing anterior depth 

 of the ramus indicates an expansion for the protection of the large 

 superior canine. 



From the same locality as the last. About the size of the Canada 

 lynx. 



Measurements. 



M. 



Length of bases of crowns of premolars I and II 0.0210 



Length of bases of crowns of premolar II 0110 



Elevation of crown of premolar II 0110 



Elevation of crown of incisor II .0055 



Diameter of crown of incisor II .0035 



Length of diastema behind canine 0110 



QUADRUMAKA. 

 MENOTHERIUM, Cope. 



Bulletin U. S. Geological Survey of Terrs., No. 1, 1874, p. 22. 



This new genus is probably quadrumanous, and allied to the lemurs ; 

 but as I only possess portions of two mandibulaT rami with dentition, a 

 more exact determination will be looked for with interest. It is the 

 first indication of the existence of monkeys in the Miocene formation of 

 the United States. 



There are at least two premolars and three molars in the inferior se- 

 ries ; those anterior being lost in the specimens. The last premolar is 

 somewhat sectorial in form, having a compressed but stout median cusp, 

 a broad heel behind, and a small tubercle in front. The last molar is 

 rather smaller than the others, and with a slight posterior or fifth 

 tubercle. The molars support four tubercles nearly opposite, in pairs^ 

 and connected by a diagonal crest, so that when the crown is worn an 

 S-shaped 'figure results. The two alveoli in front of the last premolar 

 may have contained each a separate tooth, or a single tooth, longer than 

 any of the others. The genus is apparently allied to the LeptocJicerus 

 of Leidy. 



Menotheeium lemurinum, Cope, loc. cit, January, 1874. 



CJiar. specif. — The last premolar is longer than any of the molars. 

 There are no cingula on the molars, but the transverse crest from one 

 of the tubercles descends to the side of that opposite to it, along the 

 end of the crown. Enamel smooth. Eamus of the jaw rather elongate. 



Measurements. 



Length of bases of sis molars 0.0250 



Length of bases of true molars 0120 



Length of basis of first true molar 0040 



Width of basis of first true molar 0032 



Length of basis of last premolar 0052 



Width of basis of last premolar. 0030 



Depth of ramus at last premolar 0090 



This animal was about as large as the domestic cat. 



