THE LACEETILIA. 223 



in the ventral median line, by ligamentous fibres. There is 

 no interclavicle. The pectoral arch in other snakelike 

 Lizards, such as the Blind Worm {Anguis) and the Shelto- 

 pusik {Pseudojms), is in much the same condition as in Lialis. 

 When the hind limbs are weU developed there is a com- 

 plete pelvis. The ilia are moveably articulated with the 

 fibro-cartilages which cover the ends of the sacral ribs. 

 The pubes and the ischia meet in median symphyses, and 

 the anterior margin of the pubis usually, as in the Chelonia, 

 gives off a strong curved process. In many Lacertilia a 

 partially ossified or cartilaginous rod {os cloacce) is con- 

 tinued back from the symphysis of the ischia, and supports 

 the front wall of the cloaca. 



In most Lacertilia the manus possesses five digits ; and, 

 when this is the case, there are usually eight bones in the 

 carpus — one for each metacarpal on the distal side, one 

 radial, one tilnar, and one central. As a very general rule, 

 the poUex has two phalanges, the second digit three, the 

 third four, the fourth five, and the fifth three (2, 3, 4, 5, 3). 

 The pes, also, generally possesses five digits, which increase 

 in length to the fourth, the fifth being smaller than the rest, 

 and divergent in direction. Two large bones, very closely 

 united, or completely fixed together, represent the calca- 

 neum and the astragalus, and are articulated, in a manner 

 which allows of very little motion, with the tibia and fibula. 

 In the distal row there is usually a large bone, representing 

 the cuboid. The fifth metatarsal* is bent, as in the Chelonia, 

 and may articulate with the calcaneum as well as with the 

 cuboid. One or two of the cuneiform Ijones may be present, 

 or the inner ones may be represented merely by fibrous 

 membrane, or by cartilage ; in which latter case the inner 

 metatarsals appear to articulate directly with the astra- 

 galus in the skeleton. The nu^mber of the phalanges is 

 very generally the same as in the manus for the f oui" tibial 

 toes, biit one more for the fibular (2, 3, 4, 5, 4). 



* The bone thus named may metatarsal, but the corresponding 

 perhaps contain a tarsal element, distal tarsale. 

 and represent not only the fifth 



