966 17. KINOSTERNIDE 
Synopsis OF FAMILIES 
a.—Limbs with well developed feet. 
b.—Pectoral plates not in contact with the marginals; 
plastron with two hinged, movable portions, which 
may be closed against the carapace. 
Kinosternide.—p. 966. 
b.—Pectoral plates in contact with the marginals; plastron 
not hinged, except in Terrapene. 
Testudinide.—p. 972. 
a.—Limbs modified into long, flat flippers (sea turtles). 
bb.—Carapace and plastron covered with numerous large 
horny plates; no strong longitudinal keels on costal 
region. 
Cheloniide.—p. 993. 
bb.—Carapace and plastron covered with leathery skin 
not divided into large plates; definite longitudinal 
keels or ridges on costal region. 
Dermochelide.—p. 999. 
Family 17. KINOSTERNIDZE 
This family includes a number of American turtles, of 
rather small size and aquatic habits. The shell is firmly 
ossified, and covered with large horny plates. The pectoral 
plates are not in contact with the marginals. The latter are 
23 in number. The neck can be completely drawn into the 
shell. Only one genus occurs in the area under considera- 
tion. 
Genus 49. Kinosternon 
Kinosternon, Spix, Testud. Brasil., 1824, p. 17, (type,lomgicaudatum=—= 
scorpioides). 
Cinosternum, BoULENGER, Cat. Chelonians, Brit. Mus., 1889, p. 33. 
The shell is elongate, rounded, and smooth. The plas- 
tron is firmly attached to the carapace by its central portion 
the anterior and posterior portions are hinged and may be 
