NORTH AMERICAN BATRACHIA AND REPTILIA. 
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Family CHELOHLELE. 
Body highest in front, and widest about the middle; no 
tootli-like projections on the jaws; carapace heart-shaped. 
A. Costal scales five on each side ; scales around the large 
median plate on top of head 13 to 20; scales on cheeks 15 to 20; 
cutting edge of lower jaw not serrated Thalassochelys. 
B. Costal scales four on each side; scales around large 
median plate on top of head seven. 
a. Scales on cheeks from 7 to 10; cutting edge of lower 
jaw not serrated Eretmochelys. 
b. Large scales on cheeks 15 to 20; cutting edge of lower 
jaw deeply serrate Chelonia. 
Genus Thalassochelys, Fitz. 
95. T. caouana , Linn. Loggerhead Turtle. Head low, 
broad and fiat; jaw with strong, pointed beaks; shell smooth, 
subcordiform; vertebral scales 5, costal 10, and marginal 25 to 
27; scales not imbricate; two nails to each paddle. Entire 
Atlantic coast. 
Genus Eretmochelys, Fitz. 
96. E. imbricate Linn. Tortoise-shell Turtle. Head low 
and broad ; anterior part of jaws produced forward into a pro- 
jecting bill ; scales on shield imbricated, forming thick, hard 
plates; four pairs of costals; no horny plates on neck; two nails 
to each paddle. Southern Atlantic coast. 
Genus Chelonia, Brong. 
97. O. mydas , Schw. Green Turtle. Head high an(^ nar- 
row; upper jaw slightly notched in front ; lower jaw with a small 
projection; the sides deeply serrated; body oblong; scales of 
shield thin, not imbricated; a single nail to each paddle. Atlan- 
tic coast, south of Long Island. 
Family TKIONY CHID2E. 
Head long and narrow; nostrils not subdivided by an inter- 
nal ridge; edge of upper jaw sharp, and serrated behind. 
Amyda. 
Head broad ; nostrils subdivided by a ridge which projects 
from the median wall; edge of upper jaw not serrated. 
Asjpidonectes. 
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