404 PROCEEDINGS OF UNITED STATI S NATIONAL MUSEUM. [1885. 



immediately impressed me ou account of tbeir being so disproportion- 

 ately large for an animal of its dimensions. 



For two days I kept this engaging little creature alive in my study 

 for the purpose of making a drawing of its bead and studies of its be- 

 havior and attitudes. It was then killed, carefully measured, skinned, 

 and skeletonized. 



A. glance at itg skull was sufficient to remove from my mind the last 

 of any doubt I may have entertained as to its being a half-grown wood- 

 rat. Indeed, its extraordinary ears had already fairly satisfied me of 

 this fact, as they were fully as large, or even larger, than the average 

 size of those appendages in the Neotoma. Besides, it was the wrong 

 time of the year to come across a young animal of that species, to say 

 nothing of the general appearance of maturity it evidenced both exter- 

 nally and in its skeleton. 



Concluding, then, that it was some variety of Hesperomys, I forwarded 

 the skin to my friend Mr. F. W. True, curator of the department ot 

 mammals in the United States National Museum. In his courteous and 

 prompt reply he gave me to understand that he believed it to be "a 

 typical H. leucopus, except so far as its ears are concerned." The diag- 

 nosis of course could not be conclusive, as he had not seen the skull of 

 my specimen, and even the ears had somewhat shrunken in the skin, 

 as they are sure to do. 



Here the matter rested until the 16th of May, just two months after 

 the capture of the specimen in question. On this date I was engaged 

 in hunting for insects, not a thousand yards from the tree on the hill- 

 side where my first specimen of Hesperomys was taken, but this time 

 out in the broad valley that stretches between the latter point and the 

 opposite range of hills. In turning over a heavy plank I surprised a 

 family of field mice, but encumbered as I was with ray collecting case 

 and gun, I succeeded in capturing only the male and three half- grown 

 young: the female and four more of the young ones making good their 

 escape. The young proved to be about half the size of their parents, 

 and of a deep slate color, forming a striking contrast with the light dun 

 color of the latter. 



Naturally, the first thing I examined in my new captive were his ears; 

 these I found to be of like proportions with the same parts, as I remem- 

 bered them, in eastern forms of field mice. These four specimens were 

 consigned to alcohol for future comparisons with such other material as 

 might come to hand. 



Being convinced now that my first capture was a new species, I forth- 

 with communicated with Mr, True to ascertain what could be done in 

 regard to exact identification and description, as I was desirous of hav- 

 ing the proper material before me for comparison. 



Through this gentleman's kindness I was delighted to have at my 

 command at the end of the following fortnight the subjoined list of ad- 

 ditional specimens to compare with those already in my possession : 



