402 



U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



of arched galleries of sticks and twigs, filled up with mule dung and moss, and from four to 

 eight feet long, terminating usually in a bed of moss or hair under a rock. 



This species is readily distinguished from N. floridana by its much smaller feet and rather 

 more hairy tail, as well as by the much lighter color above and on the sides. The fur is longer, 

 fuller and softer than in either N. Jloridana or N. micropus. There is no indication of the slate 

 gray of N. micropus, and it has a more densely furred tail, which also appears longer. The 

 feet, also, are even smaller than in N. micropus. Skull broader than in N. Jloridana. 



Since preparing the preceding article, a large number of specimens has been received, which 

 tend to establish the species more fully. Among them are several from the Colorado river, 

 collected by Mr. Schott, and three from the Pecos, collected by Capt. Pope. These are generally 

 similar, except that one (No. 1730) is of a light grayish slate color, lined with darker. This 

 is lighter than as described in N. micropus. I have not been able to examine the skulls, to see 

 if they agree with the characteristics derived from the first specimens. 



A very good figure of this animal has been published in the Atlas of the Voyage of the Venus, 

 taken from a specimen collected in Lower California by M. Neboux. This extends its distribu 

 tion from the Pecos river to the Gulf of California, and gives to it, compared with N. micro- 

 pus, somewhat the same range as Spermophilus spilosoma, compared with S. mexicanus. 



List of specimens. 



i Five young ones, belonging to 1329. 



NEOTOMA MICROPUS, Baird. 



Black Wood Rat. 



Ntatoma micropus, BAIRD, Pr. A. N. Sc. PhUa. VII, April, 1855, 333. 



8p. CH. Above grayish slate, beneath with feet white. Feet small. Tail hardly two-thirds the length of body ; scantily 

 haired. Feet entirely white. 



This species is about the size of the Florida rat, Neotoma Jloridana, or a little larger, an 1 

 belongs to the same section of slender tailed species. The head is broad and pointed, the 

 whiskers longer than the head, mixed black and gray. The ears are very large, broad and 



