SUBORDER A 



SIMPLICIDENTATA 



111 



Cricetodon Lartet (Fig. 139). M with five tubercles. Eocene Bohnerz; 

 Oligocene Phosphorites ; Ronzon. Lower and Upper Miocene of Europe. 



JSumys Leidy. Oligocene. White Eiver beds. 



Cricetus Pallas, ilf^ with six cusps. Recent and fossil in the Pleistocene 

 of Europe. Pliocene of Roussillon. 



Subfamily 3. Hesperomtinae. 



-§■ M. Dentition similar to that of the Cricetinae. Recent in North and 

 South America. 



Hesperomys Waterhouse (Fig. 140). Recent and in the Pliocene and 

 Pleistocene of South America. 

 A Neotoma Say. Recent and in the Pleistocene of North 



America. 



Fig. 139. 



Cricetodon cadurcensis 

 Schlosser. Phosphorite 

 near Monillac, Tarn-et- 

 Garonne, A, Upper 

 molars greatly worn 



Fig. 140. 



Hesperomys molitorVfmge. Cave 

 down. S/j (after of Bscrivania, Brazil. Inferior and 

 Schlosser). B, Lower superior aspect of skull, i/x. 

 molars. 4/^. (After Winge.) 



Fig. 141. 



A, Arvicola arvalis Blasius. B, Cuniculus 

 torquatus Pallas sp. Pleistocene of Velburg. 

 Interior aspect of mandible and superior aspect 

 of lower molars (enlarged). 



Paciculus Cope. Peromyscus Glover. In the Lower Miocene of Oregon. 

 Hahrothrix, Oxymyderus, Colomys, etc. Recent and in the Pleistocene of 

 South America. 



Subfamily 4. Murinae. Eats and Mice. 



f if. 



Cheek teeth brachyodont and with roots, upper with three, lower with two 

 rows of tubercles. 



The Murinae are animals of the Old World, but have spread over the 

 entire globe. Fossil remains have been found in small numbers in the 

 European Pliocene and Pleistocene. Asia and Africa have yielded several 

 fossil forms also, which belong to the genera Mus, Gerbillus and Nesokia. 



Mus Linn. First appears in the Pliocene of Roussillon. Acomys Geoffroy. 

 Fossil in the Lower Pliocene of Pikermi. In the Miocene of La Grive St. 

 Alban is found a Nesomyine, Anomalomys Gaillard. 



Subfamily 5. Arvicolinae. Voles. 



-| M. Cheek teeth prismatic, made up of two longitudinal rows of three to six 

 angular prisms more or less distinct. Recent in Europe and the northern part 

 of Asia and North America. 



