434: Thorpe — Som.e Tertiary Camivora in 



species, and that above M 1 is weaker. The infra-orbital 

 foramen is above the posterior part of P 3 as in C. tho- 

 bides, the type of the genus. 



This form differs from the two species previously 

 described in possessing an anterior tubercle on P 4 , as in 

 2Elurodon. However, it does not appear to invalidate 

 the generic reference, for Canis familiaris possesses a 

 well denned anterior tubercle on P 4 , while C. latrans has 

 not the least suggestion of one. P 2 possesses a posterior 

 tubercle similar to that of C. thomsoni, and unlike the 

 corresponding tooth in C. thooides. The shear of the 

 carnassial is not so transverse as in C. thomsoni, but 

 approximately the same as in the genoholotype. The 

 inner half of the superior molars is much broader than 

 that shown in the type. 



Fig. 5. — Cynodesmus cuspidatus, sp. nov. Holotype. Nat. size. Lateral 

 view of right maxillary with teeth. 



This new species is from a horizon higher than that of 

 the others. From the similarity of tooth structure and 

 the individual peculiarities of the teeth exhibited by both 

 C. thomsoni and C. cuspidatus, sp. nov., I regard the latter 

 as a derivative of the former. The type of the genus 

 shows variations, which may be due to regional isolation, 

 but whatever the cause, these seem to indicate an aberrant 

 tendency on the part of the type. The South American 

 canid, C. cancrivorus, probably shows the nearest 

 approach, among modern Canidae, to the genus Cyno- 

 desmus. 



