The Soft-shelled Turtles 



THE SPINY SOFT-SHELLED TURTLE 



Trionyx spinifer, (Lesson) 



A smaller species than the preceding, but the general char- 

 acters are very similar. The conical, spiny tubercles on the 

 front margin of the carapace are very pronounced. 



Colouration. Dull olive, with a narrow yellow border, 

 internally margined with black.* There are numerous black 

 rings scattered over the carapace a character vividly apparent 

 on young specimens, which are green. The plastron is immacu- 

 late white. 



Head markings. The head is olive not brown as with 

 the preceding species. On each side of the head, and the neck, 

 is a yellow, black-bordered stripe, extending forward and through 

 the eye thence uniting with its fellow at the base of the snout. 

 The head-markings alone will immediately separate the species 

 from the Southern soft-shelled turtle. The limbs are olive, 

 spotted and marbled with black. 



Dimensions. A mature, female specimen, taken at Quincy, 

 Illinois, shows the following measurements: 



Length of Carapace 14 inches 



Width of 12 



Length of Plastron 10 



Length of Tail 3i 



Width of Head if " 



Width of Spread, Hind Foot 3i 



Weight 7l fts. 



Distribution. An abundant species in the Central States. 

 It inhabits the tributaries of the Mississippi River in the states 

 of Missouri, Iowa, Illinois, Wisconsin, Indiana, Ohio, Pennsyl- 

 vania and western New York. It also occurs in the tributaries 

 of the St. Lawrence River, the lakes of northern New York 

 State, and has been taken as far east as Lake Champlain. 



Owing to the existence of the several canals in the upper 

 part of New York State, avenues offering an extension of distri- 

 bution have been taken advantage of by the soft-shelled turtles. 

 Thus we may understand why occasional specimens are found in 

 the Hudson River. The headquarters of this species should be 

 given, however, as the Central States. Here the turtles are so 

 numerous as to be a real nuisance to the angler. 



* Seen on all the species. 



77 



