MURIDZ. 229 
three molars is 0,0068, the dimensions of Schlosser’s spe- 
cimens ranging from 0,0067 to 0,0073. Purchased, 1884. 
Cricetodon gergovianus (P. Gervais’). 
Syn. Mus gergovianus, P. Gervais?. 
Hab. France. 
27756. The greater portion of the left ramus of the mandible; from 
the Lower Miocene of Cournon (Puy-de-Déme), France. 
The length of the space occupied by the three molars is 
0,0058, the length in the type form being 0,006 according 
to Schlosser. It is almost impossible to distinguish the 
present specimen from the mandible of the Upper-Miocene 
C. medius (No. 33269) ; and it appears quite probable that 
the two may be specifically the same. 
Croizet Collection. Purchased, 1848. 
Cricetodon sansaniensis, Lartet’. 
This species is rather larger than the Hamster. 
Hab. Kurope. 
33268. A molar tooth; from the Middle Miocene of Sansan (Gers), 
France. Presented by M. Ed. Lartet. 
48190. Three fragments of the mandible ; from the Middle Miocene 
of Steinheim, Bavaria. The length of the space occupied 
by the three molars is 0,0084. Purchased, 1877. 
Genus HESPEROMYS, Waterhouse’. 
Molars narrow, with tubercles arranged in pairs, which soon wear 
away, leaving the crown flat with indenting folds. Cranium with 
or without marked supraorbital ridges. 
Elesperomys, sp. 1. 
Hab. 8. America. 
17616. Anterior portion of the cranium of a comparatively large 
species, wanting the incisors, but showing the cheek- 
teeth ; from a cavern near Lette-Lagoas, Brazil. This 
specimen is allied to the existing H. angouya, Desm., but 
is distinct. Claussen Collection. Purchased, 1845. 
1 Zool. et Pal. Frangaises, 1st ed. vol. ii. explan. pl. xlviii. (1848-52), Mus. 
2 Loc. cit. 
3 Notice sur la Colline de Sansan, p. 20 (1851). 
4 Zoology of the Voyage of the ‘ Beagle,’ vol. i. p. 75 (1889). 
