146 



In the South they lay their eggs in May. These are about 60 in num- 

 ber, have a thick, smooth, brittle shell, and are larger than those of T. 

 muticus, being a little less than an inch in diameter. They are hidden in 

 the sand along the shores of streams. 



Dr. Baur considers the form found in the Mississippi Valley as an 

 entirely distinct species from the Te&tudoferox of Schneider. Should he 

 be correct in this judgment, as he probably is, the species above described 

 must be known as Trionyx (Platypeltis) agassizii. 



Trionyx spiniferus, LeS. 

 Sjyiny Soft- Shelled Turtle. 



Trionyx spiniferus, LeSueur, 1827, 86, 258, pi. vi; Trionyx spinifer, 

 Boulenger, 1889, 84-, 259; Aspidonedes spinifer, Agassiz, 1857, 4., i, 403, 

 and ii, pi. vi, fig. 1 (young), pi. vii, fig. 23 (egg). 



Kesembling much T. agassizii. Skull tapering gradually to the snout. 

 Proboscis with the nostrils at the tip ; these crescentic in shape, a papilla 

 projecting into each from the septum. A low obtuse keel along the middle 

 of the back. A series of spines on the front edge of the carapace, largest in 

 the females. Whole upper surface of carapace often covered with minute 

 asperities, also more prominent in the females. Tail of the male pro- 

 jecting considerably beyond the carapace. Callosities well developed in 

 the middle and hinder parts of the plastron. General color above olive 

 or light brown. In the young there are numerous ocellated spots, or 

 rings, of black all over the carapace. These may be retained until the 

 size has become considerable, but they finally become irregular blotches. 

 In the young and half grown there is a yellow border around the sides 

 and posterior edge of the carapace, and just within the yellow border is a 

 single line of black. Head olive, with a light line, margined above and 

 below with black, starting at the tip of the proboscis, forking at its base, 

 and sending a branch through each eye and down on the neck. The 

 plastron is white. Under surface of the feet much mottled with white 

 and black. 



About the size of T. agassizii. Agassiz states that the largest of which 

 be had knowledge had a carapace 14 inches long. 



This species is to be distinguished from T. agassizii by the mottled lower 

 surfaces of the feet, the line of the head, forking at the base of the proboscis, 

 and, in case the specimen is not too old, the ocellated spots of the cara- 

 pace, and the single dark line around the edge of the carapace. 



Habitat from Vermont to Montana and south to the Gulf. More 

 abundant in the Northern States. In Indiana it is the most common 

 species of soft-shelled turtle, and is so generally distributed throughout 

 the State that it is not necessary to mention localities. 



