RODENT1A SCIURINAE. 279 



CONCLUDING REMARKS. 



In the preceding pages I have presented at considerable length all the species of squirrels which 

 I have been able to identify as inhabitants of North America, north of Mexico. There are still 

 a good many species credited to the same region, which it may be as well to notice briefly for the 

 sake of completing the history of the genus. Comparatively few of these, however, if any, 

 will ever be detected within our limits, as the unexampled scientific activity of the government 

 expeditions and private parties that have recently traversed this continent in every direction 

 have left few localities unexplored. 



A considerable number of these residuary species were described at an early date by Dr. Bach- 

 man, as coming from "California." Most of them are, however, probably natives of Mexico 

 which, in its southern regions especially, abounds in large squirrels with bushy tails, and so 

 variable in color as to render it exceedingly difficult to say how many species really exist. 

 These Mexican squirrels are actually more varied in tint than those of the United States, the 



upper parts often showing the same white, yellow, or red, as the belly, in large isolated patches 



a character rarely, if ever, seen in the more northern species. In the many species described 

 by different authors, and the entire lack of Mexican specimens, I shall not pretend to determine 

 the actual number of species really existing, or to settle the question of priority of description. 

 I shall merely enumerate all that have been credited to Mexico and Central America. 



The species of Dr. Bachman may have been brought from the southern part of Sonora, 

 Mexico the distinction between the lower and upper parts of this State not being as carefully 

 drawn twenty years ago as now. It is to be regretted that no mention is made of the collector 

 of his specimens, or of the circumstances under which they were gathered ; we are equally 

 ignorant of the place where they were deposited at the time of description, or where they are 

 now. It is possible that Sciurus leporinus and lanigerus have, a real existence as North American 

 squirrels, and that the former may really be an immature S.fossor. 



I shall first proceed to enumerate the residuary species described as North American by 

 Audubon and Bachman ; then the Californian, Mexican, and Central American species, of other 

 authors ; then the South American bushy tailed species ; and conclude with a list of all the species 

 referred to, alphabetically arranged, with an indication of the page of this report where they 

 are mentioned. 



A Sciurus darkii, figured by Major C. Hamilton Smith, from a specimen in the old Peale's 

 Museum of Philadelphia, said to have been brought by Lewis and Clark from the Missouri 

 country, furnishes no characters by which it can be identified with any distinct North American 

 species. It is reasonable to presume that there is some error in the locality as given, since 

 Lewis and Clark make no mention of such an animal in their very full notices of the zoology 

 of the regions explored by them. 1 



SCIURUS CLARKII, Smith, Hab., Missouri river ? Sciurus clarkii, SMITH, Griff., Cuvier, III, 1827; 189, plate. 



"Back, upper part of the head, and neck, cheeks, and tail, of a delicate silver gray color ; the shoulders, flank, belly, 

 and posterior extremities, both within and without, white, with a slight ochrey tint ; on the sides of the nose and the fore arms 

 this tint deepens in intensity. The head is rather flatted and thick ; the ears small and round ; the eyes far apart, leaving 

 a wide expanse of forehead ; nostrils semi-lunar the upper lip cleft ; a black spot on the chin. Tail flat and spreading, 



