242 



Miocene of Sauvetat. The teeth of these specimens agree 

 precisely with those figured by Gervais (op. cit. figs. 18, 

 18 a), and are provisionally referred to Protechinomys 

 breviceps. 



Bravard and Croizet Collections. Purchased, 1848-52. 



27689. The palate, showing the cheek-dentition of both sides ; from 

 the Lower Miocene of St. Yvoine (Puy-de-D6me). 



Croizet Collection. Purchased, 1848. 



27757. The right upper cheek-dentition ; from the Lower Miocene 

 of Perrier (Puy-de-D6me). 



Croizet Collection. Purchased, 1848. 



Genus ARCHJEOM YS , Laizer and Parieu 1 . 

 Cheek-teeth rootless ; the enamel-folds continuing across the 

 crown and dividing it into laminae ; the lamina? are subequal in 

 the lower teeth, but in the upper the first lamina is the largest. 

 The genus is connected by the last with Theridomys, and leads on 

 to the Chinchillidce. 



Archaeomys laurillardi, P. Gervais 2 (ex Brav.). 

 This is the largest species ; there are four lamina? of dentine on 

 the worn crowns of the upper molars. 

 Hob. France. 



25099. Fragment of the cranium, showing the cheek-dentition of 

 the left side ; from the Lower Miocene of Cournon (Puy- 

 de-D6me), France. This specimen agrees with the type 

 cranium figured by P. Gervais in the Zool. et Pal. Fran- 

 caises, 2nd ed. pi. xlvii. figs. 15, 15 a, with the exception 

 that the length of the space occupied by the four cheek- 

 teeth is somewhat less. 



Croizet Collection. Purchased, 1848. 



25100. Part of the right ramus of the mandible, containing the four 

 cheek-teeth ; from the Lower Miocene of Cournon. 



Croizet Collection. Purchased, 1848. 



25098. Fragment of the palate, containing some of the cheek-teeth ; 

 from the Lower Miocene of Cournon. 



Croizet Collection. Purchased, 1848. 

 27674. Fragment of the left maxilla, containing the first three 



1 Oomptes Eendus, voL yiii. p. 206 (1839). 



2 Zool. et Pal. Frances, 1st ed. vol. ii., explanation of pi. xlvii. (1848-52). 



