SEXUAL CHARACTERS — ELASMOBRANCH FISHES 



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CESTRACION (HETERODONTUS) PHILIPPI 



The Port Jackson or hull-head shark 



An old and badly preserved specimen, taken at New Zealand, 

 89 cm. in length, was examined. 



The claspers are long and stout, with a flexure recalling that of 

 Mustelus (fig. 9). The apopyle, which is far removed from the 

 cloaca, leads into a deep pouch, which is continued posteriorly in 



Fig. 9 Cestracion philippi. A., position of apopyle; Ha., hamus; Hy., 

 hypopyle. 



a nearly closed tube with soft edges. A small rhipidion is 

 present, posterior to which is a blunt, hard, movable hamus, 

 with a recurved, crotchet-hke head. 



On the opposite side of the rhipidion to the hamus is a deep 

 cavity, the crumena, not similar to any pouch previously de- 

 scribed. There is a small thick-walled siphon present. 



Notwithstanding the specialization of the claspers, as regards 

 the development towards siphon formation, this genus appears 

 to be one of the most primitive of recent forms, as might perhaps 



