Allen.] 192 [December 16, 



we remember that the gopher is common in portions of Wisconsin, be- 

 ing in fact very numerous in Winnebago and Fond du Lac counties, 

 as I have myself ascertained. 



The Perognathus fasciatus may well be expected to occur in south- 

 western Iowa, since it is well known to exist in northeastern Kansas, 

 not many miles from the Iowa border. 



MURID^. 



40. Jaculus hudsonius Baird. (Jumping Mouse.) 

 Doubtless not uncommon, since it is numerous in neighboring por- 

 tions of Wisconsin and Illinois. 



41. Hesperomys leucopus Wagner. (White-footed Mouse.) 

 A species I take to be this was not uncommon. From the locality 



it may be what has been recognized by Professor Baird as the //. 

 sonoriensis of Le Conte, 1 described by the latter gentleman from a 

 specimen from Sonora. Specimens are referred to it by Professor 

 Baird from Fort Union and other localities in northwestern Dacotah, 

 and from various intermediate points southward to Texas and New 

 Mexico ; the II. leucopus of Richardson from the Saskatchawan being 

 also referred to it, it is thus recognized as having a considerable 

 range in latitude. The western limit of H. leucopus is given by Pro- 

 fessor Baird as the Mississippi. As my specimens are not appreciably 

 different from II. leucopus from Massachusetts, one is left to two 

 alternatives ; either that of regarding the H. leucopus as ranging 

 westward across the State of Iowa to the Missouri, or of considering 

 H. sonoriensis as indistinguishable as a species from H. leucopus. I 

 am the more inclined to the latter opinion from the almost exact resem- 

 blance which authentic specimens of the former that I have examined 

 bear to others unquestionably of H. leucopus. Its recognized wide dis- 

 tribution in latitude does not at all accord with its supposed limited 

 range eastward, in a region of so uniform a character as the one now 

 in question. In regard to H. sonoriensis, Professor Baird observes : 

 " This species has the general characters of the white-footed mouse 

 of the eastern States ; and it is only after the comparison of extensive 

 series that I have been able to detect differences which, though slight, 

 are so constant and of such a character as to appear something more 

 than a mere local variation. I shall, however, be obliged to indicate 

 the differences rather by comparison than as absolute characters." 



1 Mam. N. Amor., p. 474. 



