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EDWIN S. GOODRICH. 



doubt lay parallel to the ventral surface, with their sharp 

 ends pointing forwards and converging towards the middle 

 line. The posterior expansions would also extend towards 

 the mid-ventral line (fig. F). 



The structure of the skeleton of the pelvic girdle and fin 

 is of great importance as a taxonomic character. But before 

 attempting to discuss the value of these organs in deciding 

 the position occupied by Eusthenopteron in the scheme of 

 classification, it will be well to briefly compare the various 

 types of pelvic supports in the Fish series. 



Fig. C. — Ventral view of the pelvic girdle and fins of Acipeuser sturio, L. 



Amongst the Elasmobranchs we find embedded in the 

 body-wall a median-ventral cartilaginous plate, to which the 

 pelvic fins are attached by a moveable joint (Fig. A). In the 

 Holocephali there is on each side an elongated cartilage 

 supporting the pelvic fin ; these cartilages are joined to- 

 gether in the middle line by a ligament (Fig. B). A some- 

 what similar, but shorter, pair of cartilages is found in the 

 extinct Pleuracanthidse (Fig. D). A specimen in the Oxford 

 Museum (Fig. E) shows particularly well their ligamentous 

 union in the middle line. Coming now to the Teleostomi, 



