264 Bulletin American Museum of Natural History. [Vol. XII, 



a. In 1811 Echimys cristatus became the type of Loncheres 

 Illiger. 



b. In 1838 Echimys dactylinus became the type of Daciylomys 

 I. Geoffrey Saint-Hilaire. 



c. Echimys spinosus was referred by Burmeister in 1854' to the 

 genus Mesomys Wagner, who assumed (with Reinhardt, but 

 doubtless incorrectly) that Mesomys ecaudatus, the type of 

 Mesomys, was based on simply a tailless specimen of E. spinosus. 



d. Echimys cristatus and E. didelphoides are still currently re- 

 ferred to Loncheres. 



e. The remaining three species, Echimys hispidus, E. cayennen- 

 sis, and E. setosus, are still referred to the genus Echimys, as the 

 genus is now currently accepted. 



12. The genus Echimys, as now currently accepted, is not the 

 true Echimys of F. Cuvier, but Echimys as emended by I. Geoffroy 

 Saint-Hilaire in 1838 and 1840, by improperly taking E. setosus, 

 instead of E. spinosus, as the type. 



13. For the group of species now commonly referred to Echimys 

 no name hitherto proposed is available. 



In view of the foregoing it seems necessary to provide a name 

 for the group containing Echimys cayennensis, E. hispidus, and E. 

 setosus of Desmarest (1817, ex E. Geoffroy Saint-Hilaire), and 

 the allied species since described, for which I here propose 



Proechimys, gen. nov. 



Echimys I. GEOFFROY SAINT-HILAIRE, Ann. des Sci. Nat. ser. 2, X, 1838, 

 125 ; Mag. de Zool., ser. 2, 1840, 30. Not Echimys of F. Cuvier, 1809, ex I. 

 Geoffroy Saint-Hilaire, MS. 



Type, Echimys trinitatis Allen and Chapman. 



The following, besides other species, seem probably refera- 

 ble to Proechimys : 



1. Proechimys cayennensis (Desm.). 9. Proechimys chrysseolus ( Thomas]. 



2. " hispidus (Desm.). 10. decumanus (Thomas). 



3. " setosus (Desm.}. n. gymnurus ( Thomas). 



4. " albispinus (/. Geoff.). 12. trinitatis (A. & C.) 



5. " dimidiatus (Gunther). 13. canicollis (Allen}. 



6. " ferrugineus (Gunther). 14. urichi (Allen). 



7. " semispinosus ( Tomes). 15. mincse (A lien). 



8. " central is ( Thomas). 16. cherriei (Thomas). 



1 Thiere Brasiliens, I, 1854, 20 5 < 



