

I 



J 



■ ■ / , 



M 



J 



51. The spider conch, Laiuhis hunbis, is a voracious carnivore lairlv coiniiioii on coral 

 reefs. The sharp-edged operculum attached to the rear of the foot closes the shell 

 like a door. (Great Barrier Reef. Jerome M. and Doroth\ H. Schweitzer) 



■52. The painted top shell, Calliostoma zizi/- 

 ])liinum. of European Atlantic shores, does 

 not come abo\e low-tide level except in 

 favorable spots. ( Roscoff, France. I^alph 

 Buchsbaum) 



53. A Brazilian olive shell, Oliiancilhiria, from the 

 coast near Santos. When the snail is plowing 

 through sand the lustrous shell is co\"ered b\' two 

 folds of the large mantle. (Othmar Danesch) 



