966 _ 17. KINOSTERNID& _ 



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. 



Kinosternidae. p. 966. 



b. Pectoral plates in contact with the marginals; plastron 

 not hinged, except in Terrapene. 



Testudinidae. 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. 



Cheloniidae. p. 993. 



bb. Carapace and plastron covered with leathery skin 

 not divided into large plates; definite longitudinal 

 keels or ridges on costal region. 



Drmochelidae. p. 999. 



Family 17. KINOSTERNID^ 



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 



Kinoiternofi, SPIX, Testud. Brasil., 1824-, p. 17, 



scorfioides) . 

 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 



