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Head with the fore part not drawn out, the margius of the jaws not 

 concave outwardly. Snout with the nostrils at the tip ; the latter crescent 

 shaped, there being a papilla projecting into it from the septum. Body 

 with a low, obtuse keel along the middle line. Spines present along the 

 anterior border of the carapace, these largest in the males. Upper sur- 

 face of the carapace often rough with minute tubercles. Callosities of 

 the middle and hinder part of the plastron well developed. 



Color of the upper surface olive, with blotches or spots of black. A 

 light streak, margined with black, starts at the tip of the proboscis, 

 divides just in front of the eyes, and sends a branch through each eye to 

 the side of the neck. The younger individuals have a yellow boi-der 

 around the lateral and posterior edges of the carapace, inside of which are 

 two or thi:ee lines of black. The spots on the carapace of the young are 

 solid, but later in life they may become ocellated. The lower surfaces 

 are white. The bottoms of the feet are said by Agassiz to be always free 

 from mottlings of black. In a specimen which came from Mississippi, 

 however, the under surfaces of these are moderately mottled with black. 

 Agassiz states that the largest individual of this species of which he had 

 any knowledge was 18.5 inches long from the front to the hinder end of 

 the carapace. They are usually much smaller. The tail of the male pro- 

 jects beyond the edge of the carapace ; that of the female does not. 



This species closely resembles T. spiniferus. It is to be distinguished 

 by the solid spots and the two or three black lines around the carapace 

 (when not too large), the light line of the head dividing behind the base 

 of the proboscis, and the uniformly colored lower surfaces of the feet. 



This species belongs to the Southern States from South Carolina to 

 Texas. A single specimen has been forwarded to the National Museum 

 from Madison, Ind. It ought to be sought for all along the Ohio River. 



Whether or not this species is more vicious than its relatives can hardly 

 be said. But all the American species are ready to snap and bite whenever 

 they are teased, and their biting is not to be held in contempt. The head 

 and long neck can be thrust out with great rapidity, and the sharp edged 

 jaws are like scissors. Holbrook says that it will sometimes leap up and 

 give a loud hiss. He further states that it is very voracious, feeding on 

 fish and such reptiles as it can secure, and is so greedy that it takes the 

 hook readily when baited with any substance whatever. Yet he had 

 never known them to take food in captivity, even after several months. 

 They swim with great rapidity, and often conceal themselves in the mud, 

 buried two or three inches deep, leaving only a small breathing hole for 

 the long neck and small head. This it occasionally thrusts out, but usu- 

 ally keeps it concealed so that a passer-by might think the hole the resi- 

 dence of some large insect. They aie ol'ten seen basking in the sun on 

 rocks and apparently asleep. 

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