5C>8 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



are either restricted in range or altogether absent. Microtus penn- 

 sylvanicus and Peromyscus michiganensis, both abundant at Bloom- 

 ington, 35 miles north, were not found here at all. Two other grass- 

 inhabiting voles. 31. ochrogaster and Synaptomys cooperi stonei were 

 fairly common, but only in certain localities. 



Local migration of some of the small mammals was noted. During 

 the autumn a large number of traps were placed at different times 

 in a small, grass-grown area where the woods had once been cleared. 

 Among other things, a single lemming vole (S. c. stonei) was cap- 

 tured, and it seemed to be the only representative of its kind in this 

 area. Xo prairie voles (M. ochrogaster) were taken. During January 

 and again in March, White River overflowed its banks and backwater 

 extended up the creek valleys. In a little valley one-sixth of a mile 

 from the clearing above mentioned these two voles had been abundant. 

 The flood drove them away, probably drowning some, but they sud- 

 denly became abundant in the clearing, evidently having migrated 

 there through the woods. Several species of mice and shrews were 

 collected in large numbers on a railway embankment which was left 

 as a narrow island during the flood. This island formed a retreat in 

 time of high water and from this point the species afterward radiated 

 outward to repossess the bottom lands from which they had been 

 temporarily driven. 



DIDELPHIS VIRGINIANA Kerr. 

 OPOSSUM. 



The opossum is very abundant, finding a congenial home in the 

 heavy forest and among the sink holes. Most often it seems to use a 

 woodchuck hole for its home. All the specimens taken were immature 

 and were caught in traps. The young of the previous summer were 

 still immature late in January. The old animals are probably more 

 wary and are not so easily trapped. All the stomachs examined con- 

 tained remains of apples, which were abundant and easily obtained. 

 Besides apples, two stomachs contained salamanders (A. punctatum}, 

 one a frog, one a snail, one a bird, and one a mammal. 



I never saw tracks or other signs of the opossum in the caves, 

 though a piece of a mandible with a single molar was found in the 

 Shawnee Cave. 



SCIURUS NIGER RUFIVENTER E. Geoffroy. 

 FOX SQUIRREL. 



The woods of the University Farm consist principally of a heavy 

 growl h of large timber. In this large (fact but one fox squirrel made 

 its home during the winter, although there were many gray squirrels. 

 On farms in the neighborhood, where there were more open groves, 

 fox squirrels were common. Apparently they prefer the smaller and 

 more open woods. 



