RODENTIA GEOMYIJTAE GEOMYS BURSAR1US. 375 



Dr. Leconte has recently described some specimens of Geomys in the collection of the 

 Academy of Natural Sciences, and labelled as coming from the Columbia river, under the name 

 of G. oregonensis, separating them from his G. canadensis, the typical species, on account of 

 the hairiness of the tail. I have carefully examined these specimens, and can find no char 

 acters to distinguish them from the species found in Missouri. The characters given of hairy 

 tails and white chin, dark red color, and darker back, are all found equally in both ; indeed, I 

 have yet to see a reddish brown adult Geomys, having bisulcate incisors, with an entirely naked 

 tail, as an original character. I have satisfied myself that the hairs on the tail are liable to 

 fall out in patches, and especially is this the case when the vertebra are removed. 



Nor am I satisfied that these specimens were collected in or west of the Rocky Mountains at 

 all. Mr. Townsend made numerous collections from St. Louis west, and among these must 

 have been the pouched rats of Missouri, so striking to an eastern naturalist who had never before 

 seen them. Yet no mention is made of any specimens in his collections, except those of Oregon. 

 Furthermore, in the list of mammals published in his Narrative, as having been seen in 

 Oregon, this " Geomys bursarius," (as his specimens are labelled,) does not appear at all. 

 Eichardson never heard of it in Oregon ; nor have either Dr. Cooper or Dr. Suckley, who have 

 already spent more than two years in Oregon and Washington Territories, ever collected or 

 mentioned it. These gentlemen express great surprise at failing to find so many species of 

 birds and mammals mentioned by Townsend as occurring in Oregon, although their time has 

 so long been devoted almost exclusively to the natural history of that region. I fear, there 

 fore, that, in the long interval which elapsed between the collecting of his specimens and 

 their determination, owing to the loss or misplacing of labels, some at least have been referred 

 to incorrect localities. 



The accumulation of a much greater amount of material than that at my command when 

 the preceding article was written, enables me to speak more fully in regard to several matters 

 formerly in uncertainty. There appears to be little doubt that the plumbeous varieties and the 

 chestnut brown ones are the same species, as they are associated in so many localities. 



Specimens vary in the amount of hair on the tail as well in the size of the claws. As a 

 general rule, the tail is pretty closely but thinly covered with short lustrous hairs that lie flat 

 to the skin. In some specimens the extreme tip of the tail is naked, in others it is bare for the 

 terminal third. In none before me is it entirely naked. 



The size of the incisor teeth appears to vary somewhat, independently of the size of the skin, 

 and the same may be said of the claws. These become not only longer but higher and stronger 

 every way with age. The colors of the chestnut-colored specimens are generally of pretty 

 much the same tint ; the plumbago-colored ones are sometimes uniform both on back and belly ; 

 sometimes with a wash of chestnut on the belly. In all I have seen, the whole fore legs were 

 white. 



The first description of this animal was by Shaw, and was based on a drawing communicated 

 to him by General Davies of an animal said to have been brought from some portion of interior 

 Canada. It is characterized simply as " ash-colored, with short, round, nearly naked tail, 

 pouched cheeks, and the claws of the fore feet very large, formed for burrowing in the 

 ground." The figure represents a species with stuffed sacks on each side of the head, (the 



