226 RODENTIA. 



A. Molars rooted. 

 Genus NESOKIA, Gray 1 . 



Characterized mainly by the stoutness of the incisors ; the first 

 molars have three, and the others two ridges. 



Nesokia, sp. (cf. N. hardwicki, Gray 2 ). 

 Hob. India. 



16529 a. Fragment of the left ramus of the mandible, containing 

 the incisor, first molar, and the broken bases of the two 

 succeeding teeth ; from the Pliocene of the Siwalik Hills, 

 India. This specimen is noticed by the present writer in 

 the ' Palseontologia Indica,' ser. 10, vol. iii. p. 126, under 

 the name of Mus (?) sp. ; and is probably the source of the 

 statement by Falconer and Cautley, in the Journ. As. Soc. 

 Bengal, vol. iv. p. 706 (1835), that the genus occurs in the 

 Siwaliks. It is practically undistinguishable from the 

 corresponding part of the mandible of the existing Nesokia 

 hardwicki, Gray ; but, in view of the doubts as to the 

 number of existing species, it would be unwise to say that 

 it belongs to the same species, although it is quite possible 

 that this may be the case. The Eodents of the Siwaliks are 

 precisely the forms of mammals which might be expected to 

 have continued unaltered to the present day. 



Cautley Collection. Presented, 1842. 



Genus CRICETUS, Cuvier 3 . 



Molars with tubercles arranged in pairs, of which the first has 

 three and the rest two only ; these entirely disappear in aged spe- 

 cimens (Alston). 



Cricetus musculus, Pomel 4 . 

 A minute species. 

 Hob. Europe. 



26727-9. Two rami of the mandible, and two specimens of the 

 humerus and femur ; from the Pleistocene of Coudes 

 (Puy-de-D6me), France. The humerus shows the ent- 

 epicondylar foramen characteristic of the genus. 



Pomel Collection. Purchased, 1851. 

 Genus MUS, Linn. 5 



Molars with transverse ridges, each composed in youth of three 

 tubercles (Alston). 



1 Ann. Mag. Nat. Hist. vol. x. p. 264 (1842). 



2 Ibid. vol. i. p. 585 (1837), Mus. 



3 Begne Animal, ed. 1, vol. i. p. 198 (1817). 



* Cat Math. p. 31 (1853). Syst. Nat. ed. 12, vol. i. p. 79 (1766). 



