Fig. 48.— Sea Urchin. 

 [, With spines broken off; 2, with spines on. 



Fig. 49. — Molluscs— Univalves. 



HiHn ' 



Fig. 50. — Molluscs— Bivalves. 









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r^K a ""'^ 



1 , ^^Blj U 



/^ sl \v 



i'. 



K 



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«^i 





t"- 1 



\ ■« 



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/ 



/ 



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f 





Fig. 51. — Molluscs — Cuttle-fish, with eggs. 



