SEXUAL CHARACTERS — ELASMOBRANCH FISHES 



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killed in copula, by first stranding them and then administering 

 a sharp blow on the snout with a mallet. These animals were 

 preserved and dissected by me. Both claspers were inserted 

 simultaneously, the rhipidion performing the function of fixation. 



m.s.c 



m.s.c. 



Fig. 3 Galeus vulgaris, a transverse section of the wall of the siphon under a 

 high magnification; 5yu. picro-formol, alum-carmine. Ep., epidermis; c.t., sub- 

 epidermal connective tissue; b.v., blood-vessels; m.s.c., mucus-secreting cell. 



