148 ECONOMIC ZOOLOGY 



Turtles are also caught on a line baited with meat, as mentioned above. 

 In the case of the soft-shelled turtle the meat is kept near the surface 

 by a cork. Wire traps, with funnel-shaped entrances like fish traps, are 

 often used and are baited with ears of corn that become sour and attract 

 the turtles. Such traps must be examined at moderately frequent 

 intervals or the turtles may drown. The collection of fresh-water 

 turtles, in some sections, is quite an important industry. 



It is seen, then, that most of our fresh-water chelonia are of im- 

 portance to man, either as food, as scavengers, as insect-destroyers, or as 

 subjects for scientific work. 



The Hawksbill Turtle, Chelone imbricata, Fig. 99. It is from this 

 form, the smallest of the marine turtles, that the "tortoise shell," so 

 valued when made into combs and other small articles, is obtained. 

 A large specimen is about 30 inches long and may be recognized by 

 the overlapping epidermal plates. There are thirteen of these large 

 plates, which are rarely over an eighth of an inch thick; a large animal 

 will yield about 8 pounds. These plates, which are the " tortoise 

 shell," are removed by holding the animal over a fire or by immersing 

 it in hot water. It is said that the natives of the tropics sometimes re- 

 move the plates from the living animal, which is then set free to regen- 

 erate a new set of plates. This cruel expedient is of no avail as the 

 regenerated plates are probably of no commercial value. 



The thin plates are softened and worked at about 100 C. and are 

 welded together with hot irons into layers of the desired thickness. 

 Real shell generally shows the fine lines where the plates were welded 

 together, but there are so many and such perfect imitations of tortoise 

 shell that but few people are able to tell the real article from the best 

 imitations. 



India, China, Japan and the West Indies are among the great 

 centres for this article of commerce. The artificial rearing of this 

 turtle also has been suggested. 



Lacertilia. As pointed out in the preceding chapter the lizards 

 and salamanders are seldom distinguished in the popular mind, all 

 being alike called "lizards." In some sections the lizards are called 

 "scorpions," though how this misnomer should have come about is 

 hard to understand. 



Another misconception that should be corrected is the very general 

 belief in the poisonous character of the common lizards. As a matter of 



