244 Trans. Acad. Sci. of St. Louis. 



margin of posterior marginal plates slightly serrated. Nuchal narrow, 

 its hinder edge notched. Bridge wide, rising little toward the carapace. 

 Plastron slightly or not at all emarginate in front, hut distinctly so be- 

 hind. Anterior outer angles of gulars slightly produced. Axillary and 

 inguinal plates about equal. Posterior margin of anal plates angulate. 

 Head smaller in males, larger in females. Alveolar surface of jaws 

 very wide, the inner edges almost meeting. Upper jaw with the cutting 

 edge smooth, somewhat sinuated, not notched in front. Lower jaw flat, 

 not hooked at the tip. 



Color. — Carapace dark olive brown, marked all over with a network 

 of greenish lines. The tubercles of the dorsal scales are blackish. 

 Upper and lower marginals with diffused blackish sutural marks, which 

 enclose irregular lines of yellow on the underside. Head, neck, limbs 

 and tail dark green, almost black, with numerous lines and streaks 

 of greenish yellow. Behind the eye is a triangular spot of greenish 

 yellow, often elongated backward. Plastron yellow with the sutures 

 of the scutes marked with dark lines. In young specimens about 80 

 mm. long the plastron is marked with a large lyri-form blotch of brown, 

 which looks as if the colors had already faded out. 



Size. — Length of shell 180 mm.; width of same 138 mm.; depth 60 

 mm. Length of plastron on median line 158 mm. 



Habitat. — From Pennsylvania and New York to Michi- 

 gan and Arkansas. Missouri localities : — St. Louis, Stone, 

 and Jasper Counties. In Illinois, Madison, St. Clair and 

 Monroe Counties. 



Habits. — The Geographic Turtle is a truly aquatic spe- 

 cies, but is not so abundant as the preceding. It lives 

 almost exclusively on mollusks, as the unusual width of 

 the jaws would suggest. Young specimens eat thinner 

 shelled mollusks. This species together with the Cum- 

 berland and Saw-back Turtles are brought in great quan- 

 ties to the St. Louis markets. 



Genus tekkapene. 



Shell high and very convex, highest before the middle. Plastron 

 large, rounded before and behind, capable of completely closing the 

 shell. The plastron is united to the carapace by a ligament, movable 

 on it. The axillary inguinal processes rudimentary. Plastron divided 

 by a transverse hinge in two movable lobes. The hinge covered by the 

 suture between the pectoral and abdominal scutes. Entoplastron cut 

 by a suture between the humerals and the pectorals. Alveolar surface 

 of jaws narrow, without median ridge. Upper jaw with the beak pro- 



