MUKID^— S1GMODONTES— H. LEUCOPUS SONOKIENSIS. 



87 



others, the tail seems to run a little shorter than an average, but not tangibly 

 so, nor is it beyond extremes we have demonstrated for ordinary leucopus. 



The following series is from the wooded mountainous region of 

 Arizona: — 



Table XXII. — Measurements of fourteen specimens of Hesperomys, apparently SONORIENSIS, from Northern 



Arizona. 



This series* was taken in the store-houses at Fort Whipple, where. the 

 mice had taken up their quarters, and seemed as thoroughly domesticated as 

 ordinary house-mice. It unquestionably represents but a single species, read- 

 ily referable to the variety sonoriensis, which we here have in all stages, from 

 the suckling young to the adult. With the single exception below mentioned, 

 there is nothing whatever of the eremicus stamp in the series. The soles are 

 very furry indeed, owing, probably, to the fact that the animals were mostly 

 taken in cold weather; the tails are well haired and bicolor, and noticeably short. 

 In general coloration, these animals are darker than Palmer's desert examples, 

 and, in fact, not distinguishable in this respect from ordinary leucopus of New 

 England. But the ears seem to run a little larger than in Eastern United States 

 examples ; and they reach, in No. 8443, a size equal to that of eremicus. This 

 same No. 8443 also differs from all the rest in having the tail barely shorter 

 than the head and body, instead of upward of "an inch shorter, and indistinctly 

 bicolor. Its coloration leans toward that of eremicus in the pinkish-fulvous 



"It represents what we erroneously called "Hesperomys eremicus" in our article in the American 

 Naturalist, i, 3!>S ; but the name is probably correct as far as 8443 is concerned. 



