1898.] NATURAL SCIENCES OF PHILADELPHIA. 123 



Dr. J. A. Allen makes no mention of them in his publications on 

 the subject. The skulls of the two adult specimens secured by the 

 Messrs. Farnum present several characters of interest. First, as to 

 their subgeneric status, it is noteworthy that asiaticus not only has 

 the well developed and persistent second premolar found in our west 

 American species but also exhibits 6 to 8 strongly developed sulci 

 on the pigmented face of the upper incisors, analogous to those often 

 exhibited by Arctomys from the Cascade Mountains. An examina- 

 tion of several of our Cascade Mountain, Sierra Madre and British 

 Columbia species of Eutamias exhibits the same character, and in 

 some species, as T. merriami, T. quadrivittatus and T. townsendi it is 

 very marked. T. striatus and its allies of the subgenus Tamias have 

 normally smooth incisors as in Spermophilus and its subgenera Am- 

 mospermophilus and Callospermophilus. Dr. Allen's final separa- 

 tion of all American species of Tamias from T. asiaticus 6 was based 

 solely on an examination of the external characters of Siberian spec- 

 imens, considered in connection with the wide geographic separation 

 of the habitats of the most boreal forms known in Eastern Asia and 

 Western America. An English mammalogist of great note has 

 taken occasion to deplore Dr. Allen's change of arrangement of 

 American species as an illustration of the species-splitting which 

 characterizes present day methods of American mammalogists. Had 

 our critic been at the pains to inquire into the subject by personal 

 examination of specimens he would certainly have avoided choosing 

 such an illustration ; for the specific differences between T. asiaticus 

 and its nearest ally in America are, in respect of the cranium, very 

 marked. The skull of asiaticus is much larger than that of the 

 largest American Eutamias. It is also relatively much wider than 

 the skull of any American species of the genus Tamias and the great 

 width of the nasal bones contrasted with their shortness immediately 

 separates asiaticus from any other Tamias. There is a distinct supra- 

 orbital process or spine in asiaticus caused by the more posterior 

 reach of the normal supraorbital notch found in all other species of 

 the genus. The skull of No. 4,602 is 40.5 mm. long ; its greatest 

 width 22.5 mm. ; nasal length, 12.3 mm. ; posterior breadth of nasals, 

 5 mm. ; interorbital constriction 10.2 mm. Unfortunately no 

 measurements of the Mongolian specimens were taken before skin- 

 ning. The hind foot, measured dry, is 38 mm. in one specimen and 

 40 mm. in the other, indicating a species larger than striatus. 



"Bull. Araer. Mus. N.H., III, p. 45. 



