304 PROCEEDINGS OF THE ACADEMY OF 



A specimen from Utah (No. 439, Mus. S. I., formerly included 

 by Baird under G. flamis) seems to rather belong to G. parvu* : 

 the hind feet are still longer nearer 0.80 than 0.70 and the tail 

 at least as long as in No. 9856. 



As well as can be judged from the insufficient material before 

 me, this species does not differ materially in color from P. flavus; 

 and in fact the only diagnostic characters at present appreciable 

 are the greater length of the hind feet and tail. There is, however, 

 a decided difference in these respects. Further material will be 

 required to confirm the specific distinctness here accorded, or to 

 show that the two supposed species intergrade. Leaving this 

 matter, we may turn to the history of the species, some points of 

 which call for remarks. 



In the first place, it is not certain that the animal called parvus 

 by Baird in 1857, and by myself in the present instance, is really 

 the G. parvus of Peale. Prof. Baird spoke somewhat guardedly 

 in the matter, although he did not formally query his citations, 

 as I have done, and I find myself equally in doubt. Nor do I 

 see how the point is to be determined. For Peale's type, having 

 been lost or mislaid, is not at hand to testify ; and Peale's descrip- 

 tion, though elaborately detailed, will be found to consist entirely 

 of supergeneric characters, shared by all the species of Perog- 

 nathus and Cricetodipus, excepting the phrase "color above sepia- 

 brown," which is applicable to none of the species known to me. 

 The dimensions assigned agree exactly with those of the animal 

 defined in this article ; but they are equally applicable to a very 

 young Perognathus. In fine, there is no proof that Peale's genus 

 and species was not based upon a young Perognathus possibly 

 monticola. Therefore, while glad to concede that the probabilities 

 are the other way, I think it safest to query the citation of Peale's 

 animal and the compiled references that go with it; and I rest 

 upon the Perognathus parvus of Baird, about which there is no 

 uncertainty. LeConte's P. parvus, as I have already shown, is 

 really based upon a very young example of P. penicillatus. 



Baird's animal, from King's River, Cal., upon which the 

 present account is entirely based, is very immature, as shown by 

 the state of the teeth, though nearly or quite full grown. It 

 curiously resembles a very young P. penicillatus (like LeConte's 

 specimen for instance) ; and indeed, Prof. Baird was led, by its 

 immaturity and defective state of preservation, to suggest that it 



