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NORTH AMERICAN BATRACHIA AND REPTILIA. 
Genus Am yd a, Ag. 
98. A. mutica , (Les.) Ag. Fresh- water Leather Turtle. 
Back depressed; no spines on anterior margin of carapace, and 
no tubercles on back. Color above, in adult, nearly plain olive; 
in young, more or less spotted with black; below whitish, with- 
out spots. North of the Ohio river, in tributaries to the Mis- 
sissippi and St. Lawrence. 
Genus Aspidonectes, Wag. 
a. Lower surface of body and under part of feet white. 
99. A. ferox, Schw. Soft-shelled Turtle. Tubercles on 
shield in male larger than in female; in the young, two or three 
concentric black lines, separating the pale margin from the light 
brown colored back, which is studded with black dots and ocel- 
lated spots, becoming blotched in the adult. Georgia to Western 
Louisiana. 
b. Lower surface and under parts of feet spotted with 
black. 
100. A. spinifer , Les. Common Soft-shelled Turtle. A 
blunt median keel, sloping uniformly on the sides; in the young, 
a single black line about the edge of the carapace; shield olive- 
brown, with dark spots; spines less prominent in males than in 
females. North of the Ohio river, in tributaries of the Missis- 
sippi and St. Lawrence. 
101. A. nuchalis , Ag. Agassiz’s Soft-shelled Turtle. 
Marked depressions on either side oT the blunt median keel, 
which has a triangular dilation in front; spines and tubercles 
prominent in the male. Cumberland and Upper Tennessee 
rivers. 
102. A. asper , Ag. Tubercles large and coarse, behind 
supported by prominent bony warts on the osseous plates; in 
the young, two or three black lines around the posterior part of 
the carapace. Tributaries of the Lower Mississippi. 
Family CHELYDRIDAL 
Head narrow about the nose and eyes, broad behind; feet 
strong, and toes with long, strong claws; web small. 
a. Eyes lateral and distant; alveolar plate very broad; 
strong pointed projection at the symphysis of the 
jaws; three scales on each side between costal and 
marginal rows Macroc/ielys. 
