CHAr. XVII.] 



MAMMALIA. 



239 



of Panama. The geuera are as t'olluws : — Dadi/lomi/s (2 sp.), 

 Guiana and Brazil ; Ccrcomys (1 sp.), Central Brazil ; Lasiuromys 

 (1 sp.), San Paulo, Brazil; Pdromys (1 sp.), South Airica; 3fyo]Jo- 

 tamm (1 sp.), the coypu, on the East side of the Andes from 

 Peru to 42° S. lat., on the West side from 33° to 48° S. lat. ; 

 Cartci'odoii (1 sp.), Minaes Geraes, Brazil; Aulacodcs (1. sp.). 

 West and South Africa ; Mcsomys (1 sp.), Borba on the Amazon ; 

 Echimys (11 sp.), from Guiana and the Ecuadorian Andes to 

 Paraguay; Lonclwrcs (10 sp.), New Granada to Brazil. 



Fossil and Extinct Echimyidie. — The genus Cartcrodon was 

 established on bones found in the Brazilian caves, and it was 

 several years afterwards that specimens were obtained showing 

 the animal to be a living species. Extinct species of Myojjo- 

 taimis and Loncheres have also been found in these caves, with 

 the extinct genera LoncJiojjhorus and Phyllomys. 



Xo remains of this family have been discovered in North 

 America ; but in the Miocene and Upper Eocene deposits of 

 France there are many species of an extinct genus Thcridomys, 

 which is said to be allied to this group or to the next (Cercola- 

 bidie). Aidacodon, from the Upper jMiocene of Germany, is 

 allied to the West African Aulacodcs ; and some other remains 

 from the lower Miocene of Auvergne, are supposed to belong to 

 Ecliimys. 



Fathily 66.— CEPtCOLABTD.E. (3 Genera, 13-15 Species.) 



The Cercolabida', or arboreal porcupines, are a group of rodents 

 entirely confined to America^ where they range from the northern 

 limit of trees on the Mackenzie Eiver, to the southern limit of 

 forests in Paraguay. There is however an iuterveni'ng district, 

 the SoutliPin United States, from which they are absent. Ere- 

 thizon (3 sp.), the Canadian porcupine, is found throughout 



