Generic and Family Names of Rodents. 243 



is therefore quoted as 1842 and Ardomys as 1780.^ Preoccupied 

 names have been marked, and cross-references made to those 

 proposed to replace them. A few names have become ahnost 

 unrecognizable by reason of the changes they have undergone 

 in the process of emendation. Among such may be mentioned 

 the correction of Aplodontia to Haploodus, Pithecheir to Fithe- 

 cochirus, and Coelogenus to Genyscoelus.^ The original spelling is 

 always given, but no attempt has been made to include all 

 variations, although the more important have been noted. If 

 the first letter of a word has been changed, both forms have 

 been inserted in the list, but other changes have been indicated 

 in foot-notes. 



Each genus is followed by the type or species on which it was 

 based. When no type was designated and none has been indi- 

 cated by a subsequent reviser, all the species are mentioned in 

 the order given in the original description. No doubt some 

 errors will be detected here, for at first an attempt was made to 

 determine the types for as many genera as possible. This plan 

 was subsequently abandoned in favor of an enumeration of all 

 the species originally mentioned, but some cases of elimination 

 may have escaped correction. 



More or fess lack of uniformity exists in the nomenclature of 

 certain families, as, for example, in the cases of the American 

 Porcupines and Chinchillas. Thomas, considering the New 

 World Porcupines worthy of separation, erected the family Ere- 

 thizontidse, and Trouessart, a few months later, recognized the 

 same group, bat renamed it Coendidas. No less than three family 

 designations for the Chinchillas are in common use — Chinchil- 

 lidWj Eriomyidse, and Lag ostomy idse. Such a condition of things 

 is obviously unnecessary, and can only lead to confusion. As 



* While this paper was in press, my attention was called to Sherborn's 

 announcement of the discovery of Lacepede's well-known * Tableau 

 Methodique' (usually quoted 1801), in the Didot edition of Buffon's 

 Histoire Naturelle, Quad., vol. XIV, 1799 (Nat. Sci., XI, p. 432, Dec, 

 1897). Lacepede's genera Agouti, Arvicota, Coendou, Hamster, Pika, and 

 Talpoides therefore date from 1799, instead of 1801, but the necessary 

 corrections could only be inserted in the cases of Pika and Talpoides. 



'^In explanation of this remarkable emendation the author says: " Le 

 u grec ne repondant pas a I'u latin, le nom de Cuvier \_Coelogenus'] n'est 

 pas acceptable, puisqu, il renferme une faute d'orthographie ; et, pour 

 faire un nom d'apparence reellement latine, il aurait au moins fallu 

 ^crire Genyscodus et non Coelogenus.^' Liais, Climats du Bresil, 1872, p. 537, 



