220 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



Diagnosis. — Arvicola staturd inter minimos, (long, trunci B-A-poll.), formd 

 quasi- talpoidea sed rostro obtuso, caudd brevissima (subpotticari), auriculis parvis 

 rotunda /is plants subpilosis relieve occultis, pedibus exiguis, b-tuberculatis, mani- 

 bus lath dimidium pedum excedentibus, unguibus majusculis; vellere cut to, denso, 

 sericeo, supra castaneo aut brunneo, subtus cancscen/e-plumbeo. 



Little Meadow Mouse, looking something like a mole, with close silky 

 fur brown above and hoary gray below; tail shorter than the head; small 

 hind feet, with only five tubercles; comparatively large fore feet, more 

 than half as long as the hinder, and with longer claws; and small, flat, round, 

 scant-haired ears concealed in the fur. 



Habitat. — United States, chiefly east of the Mississippi, and rather 

 southerly ; north to Massachusetts and Missouri. Kansas (Goss). Fort 

 Cobb (Palmer). Oregon (U. S. Expl. Exped., Pcale). 



Some of the expressions in the foregoing diagnosis rather belong to the 

 subgenus Pitymys than to this particular species. The dentition will be 

 found fully elucidated under head of Pitymys; here we will continue our 

 account of P. pinetorum with a notice of the skull, append a table of meas- 

 urements, and then recur to external features. Nos. ttW", ? , and W2 3 , <? , both 

 from Tarborough, N. C, are more selected for description as being the most 

 perfect, but the other twelve specimens are likewise taken into account. 



Skull. — It gives an impression of being broader and more massive than 

 that of riparius; and figures do bear out the suggestion, although in truth 

 the difference in width or height, as compared with length, is slight; the 

 length relative to the width is as 92 : 57, or as 1.00 : 0.G2, on an average, 

 whereas the same proportion in riparius is 1.00 : 0.59 only. The absolute size 

 of the skull is as much less as was to have been expected from the animal's 

 smaller stature, and the difference appears to be positively distinctive; for we 

 have never seen an (adult) skull of riparius that fell below one inch, and never 

 one of pinetorum that touched this figure. Still we suspect that some Mas- 

 sachusetts skulls, for example, might reach it. Our specimens range from 

 0.90 to 0.97 in length, and the zygomatic width is just about f as much. 

 The average width of pinetorum is just at par with the minimum width of 

 riparius. There is a noticeable difference in the interorbital width, however; 

 the constriction here being no greater absolutely than that of riparius, and 

 consecpiently being relatively less. The ante-zygoniatic or rostral part of the 

 skull is perhaps broader for its length, as well as absolutely shorter. In the 



