1874.] 41 [Allen. 



that some of the farmers were accustomed to shoot them to feed to 

 their hogs, they became so scarce that but two or three could be 

 obtained in a whole day's hunt, and sometimes none would be met 

 with. From frontiersmen and hunters I have learned of deer being 

 similarly swept away and almost exterminated over quite large areas. 

 The field mice, especially the Arvicolce, it is well known are period- 

 ically excessively abundant, and again very scarce, and this variation 

 in their numbers is probably due to a similar cause. 



CERVID^E. 



13. Cervtis canadensis Erxl. Elk. Wapiti. 



Quite numerous along the Musselshell, and also on the Yellow- 

 stone above Powder Kiver, and occasional near all the larger wooded 

 streams. 1 



14. Cervus macrotis Say. Mule Deer. " Black-tailed Deer." 

 More or less frequent along all the wooded streams, and quite 



common on the Yellowstone and Musselshell Rivers. 



VESPERTILIOMD^. 



15. Lasiurus noveboracensis Gray. Red Bat. 

 Apparently not very unfrequent along the more heavily timbered 



portions of the Yellowstone and Musselshell Rivers. Often seen fly- 

 ing about camp after nightfall. 



16. Scotophilus fuscus H. All. Brown Bat. 



One specimen was taken on the Yellowstone, near the mouth of 

 the Little Porcupine. Probably more or less frequent. 



1 A yearling buck was killed on the Musselshell, which had a very singular mal- 

 formation of the left antler. It is essentially a double antler, and is attached to 

 the skull by a base three inches long by an inch in diameter. The antler divides 

 into two main parts or beams about three inches from the head, each beam sending 

 out a branch from near its base. There is no trace of a bur or enlargement at the 

 usual point, the bony portion passing higher than usual, and blending insensibly 

 with the horn proper. The anterior beam is fifteen inches long, and inclines a little 

 backward ; it sends out a branch seven inches long from near the base of its ante- 

 rior face, which in turn is also bifurcate at the end. The posterior beam is seven- 

 teen inches long, being a little larger than the anterior, and parallel with it. Near 

 the base a branch four inches long arises from its posterior face, which grows in a 

 horizontal direction, curving inwards, and nearly clasping the base of the right 

 antler. The right antler is of the usual size and form of that of a buck of this 

 age. 



