117 



the bail icadilv. oKoii eaJinj; live iiiiiiuows, which arc used in bass 

 tishing. J( swims, (Uirts and cnts I lie waU'r like a bass, and il is 

 ufteu mistaken lor a gij^autic li.sii until (he anj^h'r is alili- (o bring 

 it near enough lo sec dial he has hooked a turth' instead of a lish. 



It is the hard bon^ shell I hat most turtles lind to be their most 

 effective means of protection. This is so strong that in most species 

 when mature it will bear the weight of a man without injury. After 

 the turlle arrives at such age that it can draw it»s cxtreniilies into 

 its hard shell, it has a good means of protection and nature need 

 do little more for it. However, most of them feed by night, and 

 thus have the universal protection of darkness, given to most 

 untamed creatures. Also, many live in inaccessible swamps or 

 along streams, where they can watch the approach of their enemies 

 and [►lunge into deep water upon the slightest alarm. 



Economy: — In the economy of man the turtles till their place 

 not only as food in the form of eggs or llesh but also yield the im- 

 portant i)roduct commonly known as tortoise shell, used for making 

 vaiious ornamental and useful articles. It is especially valuable in 

 destroying many obnoxious creatures, particularly destructive in- 

 sects, and as scavengers, cleaning away dead animal material. 



Comparatively little has been said concerning the work and value 

 of tuilles as scavengers in performing their important role in Na- 

 ture by cleaning up dead animal matter in water which would other- 

 wise became a serious source of pollution. Several species of turtles 

 ar«' scavengers and play an important part in this direction, which 

 should be recognized. It is not to be presumed that the specimens 

 of birds, such as robins, and the mammals, such as rabbits, that 

 have been found in the stomachs of turtles, were captured alive by 

 these reptiles, but rather that they \\<'re found dead and eaten as 

 carrion. The details of food slmlics of each species, discussed in 

 other pagcis of this IJulletin, call attention to this fact, which is 

 here printed in such detailed positiveness and precision for the first 

 time. 



FAMILIES AND SPECIES OF PENNSYLVANIA TURTLES. 



The families of turtles represented in this Stat<' are to be deter- 

 mined by the following Analytic Key: 



A. Carapace leatln-ry, margins Hexilile; deinial plates, absent; 

 three claws on each fool; F;iMiily I. Tiionydiidji'. The Soft- 

 shelled Turtles. 



