456 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



may be said, that places permanently under water twenty-five years 

 ago are now marshes utilized for grazing during the dry season, 

 while the marshes of that period have become cultivated fields. 



Such important physical changes necessarily have a marked effect 

 upon the fauna and flora of the region. Aquatic plants and animals 

 are being reduced in number and restricted in habitat while such 

 nonaquatic species as are not held in check by man are increasing in 

 Jiumbers and extending their range. The influence of recent hydro- 

 grapliic changes is seen in the local distribution of certain species of 

 mammals which are absent from some localities now well adapted for 

 their habitat, although abundant not many miles away. This is 

 especially true of some of the members of the squirrel family, as noted 

 later. 



Trapping was carried on at three localities, which are as follows: 

 A place known as Bluegrass Landing, lying about 6 miles west of 

 the village of Roselawn in Newton County; Mountayr, a village 15 

 miles southwest of the first place and in the same county; the Koehler 

 farm, 6 miles southeast of Hebron and 2 miles from Aylesworth 

 switch on the Pittsburgh, Cincinnati, Chicago and St. Louis Railway 

 in Porter County. The first and last named places are on the banks 

 of the Kankakee River, and are "islands" or sand hills which rise 

 above the level of the marsh and are not subject to overflow. Collec- 

 tions were made at each place, both on the ''island" itself and in the 

 surrounding swamps on both sides of the river. Mountayr is situ- 

 ated near the border of the prairies, such as are found throughout 

 much of northern Indiana and Illinois, but there are marshes of small 

 area at this ])lace also. 



SYSTEMATIC LIST OF SPECIES. 



DIDELPHIS VIRGINIANA Kerr. 



OPOSSUM. 



The opossum is fairly common, though less abundant than at some 

 places in the southern part of the State. 



ODOCOILEUS VIRGINIANUS (Boddaert). 

 VIRGINIA DEER. 



Deer are said to have survived in this region as late as 1891." It 

 is not probable that any now exist here in the wild state. 



SCIURUS CAROLINENSIS LEUCOTIS (Gapper). 

 NORTHERN GRAY SQUIRREL. 

 Scivriis rnrolinmsis hypoph.a"iis Merriam, Science, VIII, 1886, p. 351. 



The Sciurus carolinensis Jiypophseus of Merriam is characterized 

 chieflj^ by the dark color of the underparts, and, so far as I am aware, 



a Butler, Proc. Ind. Acad. Sci., 1894, p. 83. 



