194 NEW SPECIES OF MICE ALLEN. 



5.3 millimetres (.21 inch.) ; nasals, 12.7 millimetres (.50 inch) ; upper 

 molar series, 5.1 millimetres (.20 inch). (Lower jaw lacking.) 



Type ilf-ff , U. S. National Museum, $ ad. Talamanca, Prof. W. M. 

 Gabb. 



This species is based on two specimens, skins, in the Gabb collection, 

 belonging to the U. S. National Museum. One still retains the skull ; 

 from the other (the type) the skull has been removed, but, unfor- 

 tunately, lacks tbe lower jaw. The two skins differ somewhat in color- 

 ation, and apparently represent different seasons of the year, one being 

 in rather fuller and darker pelage than the other. 



On the back of the labels I find written in pencil, " Near or = H. 

 laticeps Lund," a species based on specimens from Lagoa, Santa Brazil. 

 To say nothing of the wide separation of the habitats of the two, the 

 present species is very much smaller than H. laticeps^ and the resem- 

 blance in coloration is by no means close. Mr. Oldfield Thomas's Hes- 

 peromys (Oryzomys) laticeps var. nitidus, from central Peru (see P. Z. S., 

 1884, p. 452, pi. xlii, fig. 1), is also much larger than the present species, 

 and evidently very different in coloration, as he speaks of its " dark, 

 rich, rufous color." 



Hesperomys melanophrys Coues. 



Hesperomys (Veaperimus) melanophrys Coues, Proc. Acad. Nat. Sci., Phila., 1874, p. 

 181 ; Mon. N. Am. Roden., 1677, p. 102 (in part only). 



Dr. Coues in describing his Hesperomys ( Vesperimus) melanophrys con- 

 sidered it as doubtfully distinct from H. mexicanus of De Saussure. An 

 actual comparison of the types of the two species, which, through the 

 kindness of Dr. C. Hart Merriam, I recently had the opportunity of 

 making, in company with himself and Mr. F. W. True, at the U. S. 

 National Museum, has shown that they are not at all closely related. 

 I have since then been able to study more critically the specimens 

 six in all referred by Dr. Coues to this species in his final notice of 

 H. melanophrys. His original description of it (Proc. Acad. Nat. Sci. 

 Phila., 1874, p. 181) refers only to the single type specimen from which 

 it was described ; his later notice (Mou. N. Am. Roden., p. 102) refers 

 in part to other specimens, only the first three of which (given in Table 

 xxix, 1. c.), his diagnosis, and the main body of the article relate to H. 

 melanophrys. In a note to the article as originally prepared he provi- 

 sionally referred three other specimens to H. melanovhrys, though rec- 

 ognizing that they presented many points of difference, respecting 

 which he says : 



Since writing the preceding, we have examined three other specimens from 

 Tehuantepec, which, if the same, as the types of melanophrys, lessen the chances that 

 the latter is different from mexicanus [De Sans.]. But they differ in many respects 

 from the specimens just enumerated [the three originally referred to melanophrys], 

 being so very much smaller that we can not satisfy ourselves of their identity. The tail 

 only exceeds the body in one specimen, and here only a little ; in the others, it is about 

 as long, relatively, as De Saussure gives for mexicanus. That these specimens are 

 not immature is shown by the fact that one of them is a nursing female. In color, 



