MUSEUM OF COMPARATIVE ZOOLOGY. 237 



Dr. Brandt must have been much influenced by the difference in locality 

 ■whence his specimens came, in supposing there might be two species of Ere- 

 thizon, since the only difference he points out — that of the color of the tips 

 of the long hairs — is one of a trivial, and, as all mammalogists must be 

 aware, most inconstant character. The differences in the skulls discovered 

 by Professor Baird, though so appreciable, have less weight since we know 

 that skulls of individuals of the same species from the same locality not un- 

 frequently vary as much, and in the same way. Again, according to the 

 measurements he has given, and which are discussed above, one specimen 

 of the one series of three is not appreciably different from a specimen of 

 the other series of five. Hence, though having only Eastern specimens for 

 examination, I quite confidently refer, for the reasons given above, the E. 

 epixanthus Brandt to the E. dorsatus F. Cuvier. I am quite sure, also, that, 

 had either Professor Baird or Dr. Brandt possessed a good series of E. dor- 

 satus from Eastern North America, they could hardly have admitted the 

 latter's doubtfully proposed species, even provisionally. 



Prince Maximilian, in speaking of the porcupines of the Upper Missouri,* 

 mentions them simply under the generic name Erethizon, stating that he 

 was unable to decide whether the animal he observed should be referred 

 to E. dorsatus or to E. epixanthus. 



Dr. J. E. Gray, in the proceedings of the London Zoological Society ,f 

 has described a small specimen of Erethizon from Columbia as a new spe- 

 cies, under the name of E. (Echinoprocta) rufescens, although there is noth- 

 ing to indicate that it is in any way different from the young of the common 

 E. dorsatus. The differences on which he has raised it to a distinct section 

 or subgenus are only such as characterize the young or half-grown animal 

 in E. dorsatus, with which also his corresponds in size. 



LEPOMDiE. 



G7. Lepus americanus Erxl. (Emmons's Rep., p. 5(j.) White 

 Rabbit. Common, but generally less so than the next. Rare in the 

 immediate vicinity of Springfield, though numerous at localities less 

 than ten miles distant, in several directions. 



68. Sylvilagus nanus Gray.J (Lepus sylvaticus Bach. Lepus 



* Wiegmann's Archiv, XVIII, Theil I, p. 150. 



t 1865, 121, PI. XI; also in the Annals and Magazine of Natural History of the same 

 year. 



f In a recent paper entitled "Notes on the Skulls of Hares (Lepoi-idce) and Picas (La- 

 gomyidce) in the British Museum," Dr. J. E. Gray has given names to the sections of the 

 old genus Lepus, first indicated by Professor Baird in his well-studied essay on this 

 group (N. Am. Mam., pp. 572-620), and raised them to the rank of genera, thereby, of 



