608 Lake Maxinkuckee, Physical and Biological Survey 



The Map Turtle is unable to withstand a freezing temperature, 

 at least in air. During the winter several were caught where the 

 ice men had taken out ice, and were set out on the ice. They began 

 to stiffen almost immediately, and froze solid in a very short time. 

 They were very gradually thawed out by being placed in cold 

 water, but did not revive. 



The Map Turtle is probably a scavenger and does much to rid 

 the lake of dead animal matter. It also feeds largely on the smaller 

 mollusks, particularly Vivipara contectoides. It is never used for 

 food, perhaps on account of its small size as compared with the 

 two species here used for food, the Snapper and Soft-shell. So 

 far as our observations go it has no enemies except, possibly, 

 leeches. 



The Map Turtles rea.ch only a moderate size. The largest ex- 

 amples seen by us weighed 4 to 4^ pounds. 



The following table gives weights and measurements of 24 in- 

 dividuals examined: 



MEASUREMENTS OF MAP TURTLES 



No. 



The Map Turtle is usually free from growths of algas or other 

 organisms. The young differ from the older in being decidedly 

 more strongly keeled, the portions of the carapace each side of the 



