232 Trans. Acad. Sci. of St. Louis. 



emits a strong odor. I have often found them out of 

 water early in the morning. Otherwise they seldom leave 

 it. Frequently they are caught on fish hooks baited with 

 small fish or worms. Ditmars gives an experiment he 

 made with several of these turtles. He kept them in a 

 deep aquarium without means of leaving the water or of 

 obtaining a foothold on top to breathe. The test continued 

 for several weeks. These turtles either crawled along the 

 bottom of the bank or swam leisurely to the surface 

 for a breath of air. They fed readily and from all indi- 

 cations would have lived indefinitely under such condi- 

 tions. Pond turtles or River turtles — terrapins — if thus 

 treated would have soon become exhausted and ultimately 

 succumbed by drowning. The eggs are 28 mm. long by 

 15 mm. in diameter, cylindrical with spherical ends. 



88. Aeomochelys tristycha Agassiz. (Southern Musk 

 Turtle. 



Ozotheca tristycha, Sternothoerus tristycha. 



Description. — Agassiz in his Contributions to Natural History of the 

 United States, on page 425, says: "Although Ozotheca odorata varies 

 greatly, not only in color, but even in outline, I have no doubt that this 

 is a distinct species, characterized, when young, by the great prominence 

 of the keels upon the vertebral and costal plates and by numerous dark 

 dots between the scales of the sternum and, when adult, by a marked 

 difference in the form of the snout. In Ozotheca odorata the snout is 

 much more prominent on account of the slope of the upper jaw, which 

 extends further back and is therefore less steep, than in 0. tristycha, 

 the lower jaw of which is broader below the symphysis than in Ozotheca 

 odorata, and suddenly turned up." 



The upper shell is more elongated, while the forward, central shield 

 of the carapace is much narrower. 



Color. — The color of the upper and lower shields is like that of the 

 preceding species. There is a narrow stripe from the snout, extending 

 over the eye, thence back upon the neck. Beneath this is a second 

 stripe, extending from slightly above the angle of the jaw, backward 

 upon the neck. The chin has spots in place of the two light bands of 

 A. odoratus. With some specimens the head bands are very obscure. 

 These are generally old individuals and the head is brown, streaked or 

 speckled with black. (Ditmars.) 



