18 CKYPTODIRA. 



humerus is nearly straight in the Chelonidse, more or less strongly 

 curved in the other fiiniilies. The radius and ulna are subequal 

 in length, except in the Chelonida?, -wheie the former is much 

 longer and situated below the ulna and the intermedium carpi. In 

 the terrestrial and marine Chelonians, the radius and ulna are in 

 contact distally ; they are separated by the intermedium in most 

 freshwater forms. 



The carpus, in the embryo, contains nine elements, viz. the 

 radiale, intermedium, ulnare, ccntrale, and five bones in the second 

 row. All these persist distinct in the Chelydridaj, Dermatemydidoe, 

 Platysternidae, Chelonidae, and a few Testudinidce (Damonia, Mcda- 

 coclewm)/s) ■ in most Testudinidoe the radiale coalesces with the 

 centralc, and the carpals of the second row may be reduced to four 

 by fusion of two elements. A pair of additional bones, one on the 

 inner and one on the outer side, are present in Emys, Cif^tudo, 

 Geoemijdd, and Nicoria. In Chelone the outer of these additional 

 bones is larger than, and on a line with, the other carpals of 

 the second row. The number of phalanges is 2.3.3.3.3 in 

 the Chelydrida\ Dermatemydidoe, Cinosternidce, Platysternidiie, and 

 some Testudinida3 {Bc(f(«jur, Hardella, Mort-nia, Damonia, BcUia) ; 

 2.3.3.3.2 in most freshwater Testudinidae and the Chelonidae ; 

 2.3.3.2.2 in Cistw/o ■ and 2 . 2 . 2 . 2 . 2 or 2 . 2 . 2 . 2 . 1 in 

 Testndo and allie?. 



Pelvis and Hind Limb. — The ilium is loosely attached to the 

 sacrum and to the eighth costal plate. The pubis and ischium form 

 a ventral symphysis, and their symphysial branches are either widely 

 separated from each other, merely connected by a ligamentous or 

 cartilaginous band (Chelydridfe, Dermatemydida3, Chelonidae), or in 

 contact and limiting two obturator foramens (Cinosternidae, Testu- 

 dinidae). The pubis sends off a more or less developed process, 

 directed forwards and outwards, which may be subcylindrical, rod- 

 like, or flat and expanded distally : a lateral process is also present, 

 but usually less developed than that of the pubis, in the ischium of 

 all Cryptodira except the Chelonida?. An epipubic ossification is 

 present in adult specimens of Macroclemmys and Dermatemys. 



The tarsus contains two bones in the proximal row, viz. a large 

 inner (tibiale-f intermedium), in contact with both tibia and fibula, 

 and a smaller outer (fibulare) ; a centrals is distinct only in the 

 Chelydrida; ; the distal row contains five bones (if, following Hoff- 

 mann, we reckon as such the outer, larger bone which is regarded by 

 mo«t authors as the fifth metatarsal), except in the Chelonidae, 

 where only four are present. The phalanges number 2.3.3.3.2 

 or 1 in most Crvptodira ; 2 . 3. 3.3.3 in Bafaqnr, Kachmia, and 

 JlardcUu : 2 . 3 ! 3 . 3 . in CistHdo ; and 2 . 2 . 2 . 2 . in Testudo, 

 Mornopus, Py.rts, and Cim.vijs. 



