546 



University of California Publications in Geology [Vol. ll 



Mi is relatively large compared with P 4 . This tooth and P 4 are 

 both much thinner transversely than in the other species. There is 

 no suggestion of a posterior heel or of a metaeonid. A peculiar char- 

 acter exists in the extension of the concave face between the bases of 

 the protoconid and paraconid on the inner side of M x downward to 

 the cinculum. There is no alveolus for M 2 , and as the specimen 

 represents a relatively young animal without heel or metaeonid on 

 Mj it is to be presumed that the second lower 

 molar was not normally present. 



As in the case of Ischyrosmilus ischyrus, the 

 Ricardo species shows resemblance to Mackaer- 

 odus palaeindicus of the Indian Siwaliks in form 

 of the mandible, shape of the flange, and length 

 of the diastema. The Ricardo specimen and the 

 type of I. ischyrus differ from the Siwalik form in 

 the much reduced P 3 . In Mackerodus palaeindi- 

 cus according to Lydekker P 4 possesses but a 

 single posterior cusp as in I. ischyrus. In the 

 Ricardo form the posterior cusp is divided by a 

 sharp groove on the inner side, but the size of 

 the two cusps combined in the posterior lobe of this tooth in the 

 Ricardo specimen is scarcely greater than that of the single posterior 

 lobe in the type of 7. ischyrus. 



Figs. 156 and 

 157. Felid, indet. 

 Phalanges, X Mi- 

 Fig. 15 6, no. 

 21222; fig. 157, 

 no. 21313. Kicar- 

 do Pliocene, Mo- 

 have Desert, Cali- 

 fornia. 



FELID LIMB ELEMENTS 



Two phalanges, nos. 21222 and 21313 (figs. 156, 157), presumably 

 represent different species. The former represents a large cat prob- 

 ably a machaerodont. No. 21313 is much more slender and may 

 belong to a feline form. 



Measurements of Phalanges 



No. 21222 



Greatest length 37.5 mm. 



Greatest width at proximal end 22.5 



Least transverse diameter 13.5 



36.5 

 15 

 9.1 



FELID?, indet. 



A fragment, no. 21696, representing the posterior end of a 

 mandible from Ricardo is from a large form of the type represented 

 in the Barstow fauna by a similar fragment, no. 21571. The Ricardo 



