SEXUAL CHARACTERS — ELASMOBRANCH FISHES 



195 



a small tuft of dermal booklets is preserved. The fin rays , . 

 . . completely shown on the right are altogether twelve in 

 number, and the length of the supporting cartilage is scarcely 

 more than one-half of the appended clasper."^ 



8n 



6- 



2- 



cm. 



Fig. 3 Squaloraja polyspondyla, dorsal aspect, p.pb., prepubic process; 

 puh., pubic bar; il., iliac process; b., basipterygium; r., cartilaginous fin rays; 

 d., edge of skin; cl., claspers; d.h., dermal hooklets;d. t. dermal tubercles; V.c, 

 vertebral column. 



The prepubic processes no doubt formed the base of attach- 

 ment of the anterior claspers, which Parker has given reasons for 

 believing a third pair of limbs, metameric with the pelvic clas- 

 pers, making the Holocephali the sole exemplars of hexapodous 

 vertebrates. This suggestion has not met with support."* 



' Quoted from Woodward, A. S., Squaloraja polyspondyla, Proc. Zool. Socy., 

 1886, p. 527. 



* Parker, T. J., Nature, 1886, vol. 34, p. 635. 



