1894]. XATURAL SCIENCES OF PHILADELPHIA. 253 



DESCRIPTIONS OF FOUR NEW SPECIES AND TWO SUBSPECIES OF 



WHITE-FOOTED MICE FROM THE UNITED STATES AND 



BRITISH COLUMBIA. 



BY SAMUEL N. RHOADS. 



The North American genus SUomijt<, comprising the white-footed 

 or deer mice, has received accessions in the last ten years which bring 

 the combined number of species and subspecies from twelve, in 1885, 

 to thirty-seven in 1884. It may appear presumptive to offer for con- 

 sideration six additional names to this already rather appalling list 

 of rodents belonging to a single genus. It is somewhat assuring, 

 however, to read the statement of Dr. J. A. Allen,' in his paper on 

 Recent Progress in the Study of North American Mammals, that 

 most of these forms are not only "well founded," but that he 

 is "cognizant of still undescribed forms entitled to recognition in 

 nomenclature.' ' 



It may be stated, that in every case the following diagnoses are 

 based on a critical comparison of both external and cranial char- 

 acters with a large series of allied forms from the same region, and 

 in the case of full species the separation has been mainly founded on 

 the characters of the skull. 



Sitomys megacephalus is represented by a single adult and two 

 young specimens in alcohol from northern Alabama, While it is 

 desirable that more specimens should be examined, its characters 

 diverge so widely from its nearest geographic allies, I can offer no 

 apology for presenting it now. 



Sifomijs insolafus is based on a single individual from the Mohave 

 Desert, California, while a second specimen from the Mohave River 

 in transitional pelage is provisionally referred to it. The collec- 

 tions of the Academy of Natural Sciences contain a large series of 

 Sitomijs from the neighboring regions of Southern California, 

 and the same is undoubtedly the case with the collections of the 

 Department of Agriculture; yet I find in insolatus no close corre- 

 spondence to any other mouse I have yet seen or read description of 



1 Proc. Liun. Soc, N. Y., 1894. 



