178 DR. C. W. ANDREWS ON LOWER MIOCENE [June 1914, 



two closely-united cusps, the outer of which is united with the 

 postero-external cusp, while the inner is separated from the middle 

 transverse crest by a well-defined valley extending half way across 

 the crown. 



These teeth seem to be very similar to the lower teeth of 

 Phiomys described by Prof. Osborn, 1 while they differ considerably 

 from the lower teeth doubtfully referred by Dr. Schlosser 2 to that 

 genus. The chief difference between the molars and those of the 

 Phiomys of Osborn seems to be that the incomplete crest, running 

 on from the postero -internal side of the protoconid, is less developed 

 than in that genus. In Metaphiomys, on the other hand, it is 

 much more strongly developed. 



The dimensions (in millimetres) of this specimen are: — 



Length of the crowns of the three teeth 10*6 



Length of crown. Width of crown. 



pm t 4-0 3-8 



m l 3-4 4-0 



m, 3-8 4-2 



Measurements taken at the grinding- surface. 



Dr. Schlosser has shown that Phiomys is a member of the 

 Theridomyidae, approximating in tooth-form to various species 

 of Theridomys and Trechomys, and the species here described may 

 be regarded as belonging to a new genus of the same family, its 

 specific name being P ar a phiomys pigotti, gen. et sp. nov., 

 after the late Mr. D. B. Pigott. who was the first to collect bones 

 in this locality. It may have been derived from Phiomys or some 

 allied form, having undergone an increase in size and a reduction 

 of the transverse ridge mentioned above. 



Of the recent forms inhabiting Africa, the Cane -Rats seem to 

 approach this type most nearly in tooth-form. For instance, in 

 Thryonomys the molars are similar, but have entirely lost the 

 extra ridge from the protoconid, and the premolar is larger and 

 more complicated. Much more material is required before the 

 question of any actual relationship can be settled. 



Order CARNIVORA. 



This order is represented by a portion of the left ramus of a 

 mandible and a left astragalus. 



The mandibular ramus (PI. XXIX, figs. 1 a & 1 b), from Bed 31 

 at West Kachuku, is unfortunately incomplete posteriorly, all 

 behind the last premolar having been broken away. That portion 

 of the ramus which is preserved deepens at the symphysis, partly 

 on account of the upward curve of its upper border, but partly 

 also owing to the slight downward curve of the ventral border to 

 the rounded and thickened chin. There are two foramina on the 



1 Bull. Am. Mus, Nat. Hist. vol. xxiv (1908) p. 269. 



2 Beitr. Palaont. (Esterr.-Ung. vol. xxiv ; pt. 2 (1911) p. 91. 



