228 A NATURALIST IN THE GREAT LAKES REGION 



Pennsylvania (Fig. 316), Tenebrio tenebrioides (Fig. 317), Uloma 

 impressa, Meracintha contracta are all beetles more than half an 

 inch long that are common in such situations. All belong to 

 the family of darkling beetles, and the list might be much 

 extended. 



Then as decay becomes more complete other forms largely 

 replace those listed above, although some of these, as for instance 

 Passalus cornutus, remain even in well-decayed wood. The 

 rotten-log caterpillar, Scolesocampa, also is found from early to 

 late stages. 



FIG. 315 FIG. 316 FIG. 317 



FIGS. 315-317: Fig. 315 Oak borer, Eupsalis minuta. After Felt; Fig. 316. 

 Beetle, Nyctobates pennsyhanica; Fig. 317. Beetle, Tenebrio lenebrioidcs. All X2. 



The transition from the upland forest to the surrounding 

 prairie is accomplished through a characteristic forest margin 

 association. For the oak-hickory forest that is so commonly 

 the climax on the morainal hills in the immediate vicinity of 

 Chicago this consists of the wild crab often draped with the wild 

 grape, the trembling asp, the hawthorns, an occasional wild 

 plum, the smooth and staghorn sumacs, hazelnut, nannyberry, 

 and other viburnums, and not uncommonly some of the dog- 

 woods. The spring and summer herbaceous plants are not 

 materially different from those of the adjacent forest. The May 

 apple may make a goodly showing, the Canada and spear 



