LAKE TO FOREST OR PRAIRIE 



239 



rice (Fig. 338); water-reed, Phragmites communis (Fig. 339); 

 sweet flag (Fig. 340). 



Along the margin of the open water soft-shell, musk and 

 geographic turtles are to be expected. The first is easily known 

 by its leathery rather 

 than bony shell; the 

 second, by its musky 

 odor; the third, by 

 the fine lines on each 

 bony plate of the 

 shell that give an 

 appearance some- 

 thing like a map. 

 Farther in shore in 

 the zone of submerged 

 plants, especially in 

 the bays, are many 

 adult and larval in- 

 sects that may be 

 dredged up with the 

 plants. The top min- 

 now, Fundulus dispar, 

 is common (Fig. 434). 

 Among the insects are 

 the water scorpion, 

 giant water bug, 

 water boatman, many 



FIG. 341. The painted turtle 



diving beetles of the 

 families Dytiscidae 

 and Hydrophylidae, and May-fly nymphs. Dragon and damsel- 

 fly nymphs are common, and the molt skins of the latter are 

 commonly found on the rushes and cat-tails. A few of the 

 more frequent dragon flies are Anax junius, Gomphus spica- 

 tus, and Libullula pulchella. These insect larvae are already 

 familiar from the study of the interdunal ponds, as are also the 



