Mammals of Porter County 211 



About the edges of such meadows and ponds the sour gum, Nyssa 

 sylvatica is found quite characteristically. Although such places appear 

 to be quite ideal for many species of mammals, yet comparatively few 

 runways or other signs of mammals were found in them. The species 

 taken were the common deer mouse, Peromyscus leucopus novehoracen- 

 sis; on one occasion, the Baird deer mouse, P. maniculatus bairdii; 

 prairie and pine voles, Microtus ochrogaster and Pitymys pinetorum 

 scalopsoides, and the short-tailed shrew, Blarina hrevicauda taljjoides. 



Subdtinal sivarnp or marsh: Between the tracks of the Chicago, 

 Lake Shore and South Bend Railway and the dunes proper is an ex- 

 tensive area of low ground, almost as low as the level of Lake Michigan. 

 At Mineral Springs station the track is said to be 13 feet above the 

 lake level and the track is higher than the swamp. Part of this low 

 ground drains into the lake at Waverly Beach by Dune Creek. Toward 

 Michigan City much of this low ground is being cultivated and from 

 most of the other treeless portions much hay is cut. Most of the sub- 

 dunal swamp or meadow is treeless, but near the dunes in many places 

 it is timbered with such trees as tamarack, Larix laricina; white pine, 

 Pinus strobus; yellow birch, Betula lutea; occasionally, paper birch, 

 B. papyrifera; red maple, Acer riibrnin; elm, Ulmus americana; speck- 

 led alder, Alnus incana; and tupelo, Nynsa sylvatica. A conspicuous 

 shrub in this area is the poison sumac, Toxicodendron vernix. Opposite 

 Mineral Springs this wooded portion is usually termed the tamarack 

 swamp although tamaracks are by no means the most common trees. 

 Farther west white pines predominate, in places the floor being almost 

 solid with their needles. Parts of this subdunal swamp are very boggy, 

 containing such vegetation as pitcher plants, Sarracenia purpiirea; 

 cranberry, Oxycocctis macrocarpus, etc. In many places it is compara- 

 tively easy to sink to considerable depth in the more boggy portions. 

 It is in such places if they should ever be explored or drainage ditches 

 cut into them that one might expect to find remains of large mammals, 

 elk, deer, bison which had become mired there years ago when such 

 species were common in Indiana. In this subdunal swamp traps were 

 placed in various sections excepting in the extremely boggy areas. The 

 deer mouse, Peromyscus leucopus noveboracensis, was the common mam- 

 mal. In the open portions of the marsh rattle-snakes, Sistrjirus cate- 

 natus are frequently taken, especially during haying. 



D^ine Creek: This is a small sluggish stream draining part of the 

 subdunal swamp. It starts in the Furnessville region and flowing slowly 

 westward and northward empties into Lake Michigan just west of 

 Waverly Beach. Most of its course is through swampy woods. Owing 

 to lack of time no trapping was done along its course. 



Mammals Collected in the Dune Region of Porter County or Mam- 

 mals Observed in the Region. 



Opossum (Didelphis virginiana Kerr) : A few years ago near 

 Dune Park Dr. and Mrs. W. D. Richardson found the dead body of a 

 mature opossum and on another occasion found a half-grown young. 



Prairie mole (Scaloptis aquaticus machrinus Rafinesque) : Residents 



