488 BULLETIN 58, UNITED STATES NATIONAL MUSEUM. 



Suborder LAMIMFERA. " 



1820. Laminifera IIempricu, Gniudr. Naturg., [). 102. 



1880. Aspidochelyidae Seeley, Quart. Journ. (irul. Soc, XXXVI, ]>. 412. 



1895. Cerachelya H.eckel, Syst. Phylog. Wirbelth., p. — . 



. This suborder, which comprises the Cryptodira uiul Pleurodira of 

 Cope and many later authors and which equals Dollo's TJiecophora 

 minus the soft-slielled turtles, as well as Baur's Paradiacosfoidea 

 minus the leather-back turtle, is trench antl}^ characterized by the 

 horny plates which externally cover the shell. 



Hem])rich, as early as 1820, established the present division as 

 opposed to- that of the Athecse. plus Chilotse., which he designated col- 

 lectively as Coriacea} 



The hornv-shelled turtles belong to two different superfamilies, the 

 Tfsfudinoidese, corresponding to the group Cryptodira, and the 

 Chelydoidex, equaling the Pleurodira, but only members of the former 

 enter our limits, as at the present day the latter are confined to the 

 southern hemisphere. Of the numerous families composing the Tes- 

 tudinoidese only tw^o are intralimital, viz, the marine turtles, with 

 paddle-shaped limbs having less than three claws, and the subfamily 

 Emydinx of the family Testudinidis, having normal limbs with more 

 than two claw^s. 



Family TESTUDINID.E. 



Sribfaiiiily E;m:YDIIS"JE. 



Web-footed turtles having the nuchal plate without costiform 

 lateral processes. 



The terrapins constitute the bulk of the species and genera of turtles, 

 widely distributed in the temperate and tropical countries. They 

 live in streams, lagoons, or on land, and are both vegetable and animal 

 feeders. Some species are highly esteemed as delicacies. 



SYNOPSIS OF THE EMY^DINE GENERA OCCURRING IN JAPAN, FORMOSA, AND KOREA. 



fli Plastron not hinged; plastron and carapace joined by suture. 



6' Triturating surface of upper jaw with a longitudinal median ridge. .Ocadia, p. 489. 

 h- Triturating surface of upper jaw without a median ridge. 



& Choanie behind level of eyes; skin of hinder part of head divided into small 



shields Geoclemys, p. 496. 



c- Choanae between the eyes; upper surface of head with undivided skin. 



d' Hexagonal neural plates with the anterior lateral edge shorter than the 



posterior lateral edge Clemmys, p. 492. 



d^ Some of the hexagonal neural plates with the anterior lateral edge longer than 



the posterior lateral edge Geoemyda. p. 500. 



a^ Plastron hinged; plastronand carapace joined directly by ligament. C'j/c^emys, p. 503. 



ttFrom lamina, a thin plate [of horn, in this case], and fero, I bear. 

 &Grundr. Naturg., 1820, p. 101. 



