520 



MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



in 1857, and l)y myself in the prescnl instance, is really the C. parvus of 

 Poiilc. Professor Baird spoke guardedly in the matter, although he did not 

 formally query his citations, as I have done, and I find myself equally in 

 donI)t. Nor do I see how the point is to be determined. For Peale's type, 

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

 tliongli elaborately detailed, will be found to consist entirely of supergeneric 

 characters, shared by all the species of Perognathus and Cricetodipus, except- 

 ing the jdirasc "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 

 were not based up(m 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 tlie 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 doubt- 

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



Baird's animal, from King's River, Cal., is very immature, as shown by 

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

 bles a very young P. penicillatus (like LeConte's specimen for instance) ; and, 

 indeed. Professor Baird was led, by its immaturity and defective state of 

 preservation, to suggest that it n)ight not impossibly belong to P. penicillatus, 

 though he proceeded to m!,'e it the basis of his P. parvus. It is, however, 

 unquestionably a Cricetodipus, as I can affirm without qualitication from 

 inspection of the skull, which clearly shows the bulge of the mastoid back of 

 an occipital emargination and other cranial characters diagnostic of Cricetodi- 

 pus, to say nothing of the hairy soles and unlobed antitragus. I therefore 

 accept the species as first clearly defined by Baird, without necessarily involv- 

 ing the question by including the doubtful animal of Peale. 



As already suggested, the chances are that Baird was right in identifying 

 his species with that of Peale, so that the name Cricetodipus parvus will prob- 

 ably stand. But should the contrary prove to bo the case, and Cricetodipus, 

 Peale, 1848, be conclusively shown to be a synonym of Perognathus, Maxim., 

 1839, a new name, geno-ic and specific, will be required for the subject of 

 the present article. The name OrooNosis would be ai)propriatc, in allusion 

 to the facility vith which the species may be distinguished from those of 



