Xo. 472] ANATOMY OF CRYPTOBRANCHUS 



305 



The posterior articular processes (Fig. 7, P. A.) have a rounded 

 outhne, as seen from above, and are flattened ventrally where 

 they articulate with the underlying anterior processes of the siit- 

 ceeding vertebra. The anterior articular processes (Fig. 7, .1.) 

 do not differ greatly from the posterior, except in having their 

 articular surfaces on the dorsal instead of the ventral side. The 

 vertebne of the body region resemble each other so strongly in 

 shape that it would be very difficult to say from just what part of 

 the body any given vertebra had been taken, but in an individual 

 skeleton the vertebrae in the middle region of the body are both 

 longer and heavier than those anterior and posterior to them. 



The sacral vertebra differs from those immediately in front 

 and behind it only in the much greater development of the trans- 

 verse processes (Fig. 6, S.), and the ribs. The sacral ribs, since 

 they serve for the attachment of the pelvic girdle, are much heavier 

 and stronger than any of the other ribs. Instead of projecting 

 as sharp points straight out from the body, they curve downward 

 and end in articular surfaces for the attachment of the upper ends 

 of the two rods of the ilium. 



The caudal vertebrae present more variations both in size and 

 form than do those of the body. The first caudal vertebra so 

 closely resembles the last body vertebra that it would be very 

 difficult, if not impossible, to tell them apart. The third caudal 

 vertebra may be described as a type of those of this region (Figs. 

 6 and 8). The chief differences between this vertebra and the 

 typical body vertebra are, besides the smaller size of tlie former, 

 the weaker transverse processes, the larger dorsal >pino. and the 

 presence of a well developed haemal arch. TransxeiNf protcsses 

 are found on the first eight of these vertebra-, and an- provKk-d, 

 at least in the case of tlie first fotir or five, with minnte H!.>. These 

 processfs diminish in size from before backwanh so that those 

 of the vh^hxh <-au(hd vertebra are very small ( Fi.u'. C i. Thv dor.al 

 spines, on the otlier hand, become more prominent from l>efore 

 backward, until tliey reach their greatest development in tlie mid- 



As the caudal vertelmv become m<.re and more .-ompre^^cd later- 

 ally, the posterior articular processes approach each other nntil, 

 in the midcaudal region, they are not (listiii^mshablc troni the 



