= 
= 
230 RODENTIA. 
Hesperomys, sp. 2. 
Hab. §. America. 
17616 a. Anterior portion of the cranium, and two rami of the 
mandible; from the caverns of Minas Geraes, Brazil. This 
cranium is smaller than the last, and has not been identified 
with that of any living species. 
Claussen Collection. Purchased, 1845. 
‘Hesperomys, sp. 3. 
Hab. 8S. America. 
18898. Middle portion of the cranium, showing the cheek-teeth ; 
from a cavern in Minas Geraes, Brazil. The teeth of 
this species are larger than those of the last. It comes 
nearest to the group Oavymycteris. 
Claussen Collection. Purchased, 1845. 
Hesperomys, sp. 4. 
Hab. 8. America. 
18897. Anterior portion of the cranium, showing all the dentition; 
from a cavern in Minas Geraes, Brazil. This specimen 
belongs to the group Habrothrix, and comes nearest to the 
existing H. arviculoides, Pictet. 
Claussen Collection. Purchased, 1845. 
B. Molars semirooted or rootless. 
Genus ARVICOLA, Lacépéde’. 
Molars rootless (rarely semirooted), separated into prisms, which 
are placed alternately. 
Arbicola amphtbtus (Linn.”). 
Syn. Mus amphibius, Linn.’ 
Four outer and five inner angles in first lower molar; three outer 
and two inner angles in second upper molar; molars rootless 
throughout life. 
Hab. Europe and North Asia. 
15081. Anterior portion of the cranium and three imperfect rami of 
(Fig.) the mandible; from Kent’s-Hole Cavern, Torquay. The 
cranium and one ramus of the mandible are figured by 
Owen in the Brit. Foss. Mammals and Birds, p. 201, fig. 76. 
McKnery Collection. Purchased, 1842. 
» Mém. de l'Institut, vol. iii. p. 495 (1801). , 
2 Syst. Nat. ed. 12, vol. i. p. 82 (1766), Mus. 3 L0G, Clie 
