1899-] Allen, The Generic Names Echimys and Loncheres. 263 



Geoffrey Saint-Hilaire, and was exclusively based on (i)"le 

 Lerot a queue doree " of Allemand (in Buffon), named Myoxus 

 chrysurus by Zimmermann in 1780, and Echimys cristatus by 

 Desmarest (ex E. Geoffrey, MSS.) in 1817 ; and (2) le "Rat 

 epineux " of Azara, named Echimys spinosus by Desmarest in 

 1817 (ex E. Geoffroy MS.). 



3. In 1812 F. Cuvier further characterized the genus Echimys, 

 from the same two species above named. 



4. Therefore one of these two species, as they are not con- 

 generic, must be taken as the type of Echimys. 



5. Illiger, in 1811, established the genus Loncheres, referring 

 to it two species, namely, (i) L. paleacea, a species not described 

 till nine years later, and (2) " Hystrix chrysuros LinGmel.," = 

 Myoxus chrysurus Zimm. 



6. As an undescribed species cannot be taken as the type of a 

 genus, Myoxus chrysurtis Zimm. ( = Echimys cristatus Zimm.) 

 becomes the type of Loncheres. 



7. This, by the process of elimination, leaves Echimys spinosus 

 Desm. as the type of Echimys. 



8. Nelomys Jourdan (1837), based on a species {Nelomys blain- 

 villii Jourd.) currently recognized as congeneric with Echimys 

 cristatus Desm. (= Myoxus chrysurus Zimm.), is therefore a pure 

 synonym of Loncheres. 



9. Mesomys Wagner (1845) was based on a species (Mesomys 

 ecaudatus Wagner) currently treated as congeneric with E. 

 spinosus Desm., arid is therefore in all probability a pure synonym 

 of Echimys. If otherwise (I am unable to find a satisfactory 

 account of the dentition of Mesomys), Mesomys will not conflict 

 with Echimys. 



10. In 1817 Desmarest described the following seven species 

 under Echimys, adopting therefor E. Geoffroy Saint-Hilaire's 

 manuscript names. These species are : 



1. Echimys cristatus. 5- Echimys didelphoides. 



2. Echimys dactylinus. 6. Echimys cayennensis. 



3. Echimys spinosus. 7- Echimys setosus. 



4. Echimys hispidus. 



11. The subsequent history of these species, in relation to the 

 genus Echimys, is as follows : 



