LIMBS OF THE CROCODILE. 115 



larynx. The long, bony "ceratohyal," and tlie commonly 

 cartilaginous " epihyal," are suspended by the ligament- 

 ous " stylohyal" to the paroccipital process ; the whole 

 arch having, like the mandibular one, retrograded from 

 the connection it presents in fishes. 



This retrogradation is still more considerable in the 

 succeeding haemal arch. In comparing the occipital seg- 

 ment of the crocodile's skeleton with that of the fish, the 

 chief modification that distinguishes that segment in the 

 crocodile is the apparent absence of its haemal arch. We 

 recognize, however, the special homologues of the con- 

 stituents of that arch of the fish's skeleton in the boues 

 51 and 52 of the crocodile's skeleton (Fig. 18) ; but the 

 upper or suprascapular piece, 50, retains, in connection 

 with the loss of its proximal or cranial articulations, its 

 cartilaginous state; the scapula, 51, is ossified, as is like- 

 wise the coracoid, 52, the lower end of which is separated 

 from its fellow by the interposition of a median, symme- 

 trical, partially-ossified piece called " episternum." The 

 power of recognizing the special homologies of 50, 51, 

 and 52 in the crocodile, with the similarly-numbered 

 constituents of the same arch in fishes — though masked, 

 not only by modifications of form and proportion, but 

 even of very substance, as in the case of ,50 — depends 

 upon the circumstance of these bones constituting the 

 same essential element of the archetypal skeleton, viz;, 

 the fourth haemal arch, numbered j9?, 52, in Fig. 7 : for 

 although in the present instance there is superadded, to 

 the adaptive modifications above cited, the rarer one of 

 altered connections, Cuvier does not hesitate to give the 

 same names, " suprascapulaire" to 50, and "scapulaire" 

 to 51, in both fish and crocodile ; but he did not perceive 

 or admit that the narrower relations of special homology 



