EXPLANATION OF PLATE VIL 



K. Pristiurus embryo hardened in chromic acid. 7/" 



The remainder of the figures are representations of embryos of 

 ScyUium canicula hardened in chromic acid. In every case, with the ex- 

 ception of the figures marked P and Q, two representations of the same 

 embryo are given ; one from the side and one from the under surface. 



