NATURAL SCIENCES OP PHILADELPHIA. 299 



distinctive characters in this group. We may suppose the animal 

 to be a Perognathus, from the general tenor of Dr. Gray's remarks, 

 and his curiously mixed up quotations ; and it is perhaps P. mon- 

 ticola, as that species has conspicuously soft hair in comparison 

 with some of its allies, and is of about the dimensions assigned. 



Specimens of any Saccomyine form from Oregon and Washing- 

 ton Territory are at present special desiderata. 



On the same page quoted, Dr. Gray describes a new species of 

 Perognathus in the following terms: 



" PEROGNATnUS BICOLOK, B. M. 



" Perognathus monticola, Gerrard, Cat. Bones B. M. (not Baird). 

 Black ; upper lip, lower edge of the cheek-pouch, head, and under 

 side of body and inner side of limbs white. Fur uniform bristly; 

 bristles elongate, slender, with a slender point, and intermixed 

 with very slender elongated hairs. Tail as long as the body, with 

 rings, square scales, and short bristly hairs. 



"Hah. Honduras (Salle). 



" There is a Spiny Bat from Honduras 1 with a longer tail and 

 smooth front teeth, agreeing in color with the above." 



1 have never seen a black and white Perognathus, nor one in 

 which "bristles" were mixed with "slender elongated hairs;" 

 but seeing the state of the fur in P. hispidus should not be sur- 

 prised at any degree of rigidity the hairs of a species might de- 

 velop further south. 



A " Perognathus fasciatus Salle" (nee auct.) is noticed by Gray 

 (torn, cit.), p. 205, as a synonym of his Eeteromys irroratus, n. 

 sp. from Oaxaca. This is said to agree with the description of 

 " H. [i. e. P.] fasciatus," but to have smooth upper incisors, etc. 

 Gray calls the fur of Heteromys " flat channelled spines." There 

 is nothing of this character in Perognathus, where the most rigid 

 fur of any United States species would scarcely warrant the term 

 "bristly." It is unexpected to find species of Perognathus, of 

 two authors, quoted among the synomyms of Heteromys. 



1 Characterized on p. 204 as Eeteromys melanoleucus, with " Perognathus 

 monticolor, [sic] Gerrard, B. M. not S. Baird," quoted as a synonym. 



