512 MONOGBAPH8 OF NOETH AMEBICAN UODENTIA. 



over, it so happens that the left ear of the type is in sufficiently good preser- 

 vation to enable me to clearly recognize the peculiar conformation which 

 distinguishes the presenl species from the others. 



To this same species I am also inclined to refer two specimens recently 

 collected by Mr. II. W. llenshaw on Otter Creek, in Utah. These are appar- 

 ently young animals, but, as they are not accompanied with the skulls, the 

 fact cannot he determined.* The tail of each has been skinned, and is now 

 so shrivelled that nothing can be predicated as to its length, either relative! or 

 absolute. The specimens are quite small ; they have been overstuffed, meas- 

 uring now about 2A inches, but were probably not much, it' any, over 2, with 

 a hind foot of 0.80 ; in fact, they might be taken at first sight for Criceiodipus. 

 But the soles arc naked along a narrow strip quite to the heel; the antitragus 

 has a very prominent lobe; and even from the dried skins I determine, with 

 no appreciable chance of mistake, that the ear has the other peculiarity of P. 

 monticola. The pelage is remarkably soft; the coloration is different from 

 that of any other PerognatJii I have seen, being plumbeous (like the plum- 

 bago-colored specimens of Georhys and Thomomys), with little admixture of 

 lighter color; and the soles show a decided fulvous stripe. But these speci- 

 mens exhibit the fore leg colored quite to the wrist, and I am inclined to 

 attribute the dark color to their immaturity. I shall therefore assign them to 

 P. monticola. 



The four specimens noticed are the only ones which have come under 

 my observation. To sum the case in a few words, we have here an animal 

 unquestionably distinct from any of the other species described in this paper, 

 the only question being whether all the specimens referred to it are specifi- 

 cally identical. They ostensibly differ to a degree that might have caused 

 them to be described as distinct at the period when Professor Baird's work 

 was prepared. This question must await the reception of additional material 

 for its satisfactory solution. I can only say that I am at present unable to 

 see more than one species. Should the contrary be determined, the present 

 article is. to be held as based upon the Fort Crook specimen, for which I 

 have suggested the name of P. mollipilosus as a provisional designation. 



* Since tliis was written, Mr. Hensbaw tells nie the animals are very young indeed — they had not 

 left the nest when captured. These are the specimens doubtfully noticed by Dr. Yarrow and myself, in 

 Wheeler's Report, s. o. 



