138 POPULAR CONCHOLOGY. 



According to Mr. Scoresby, it is found in great 

 profusion near Spitzbergen. 



5. Cymbulia. — Shell gelatinous, cartila- 

 ginous, very transparent, crystalline* 

 oblong, in the shape of a shoe, 

 truncated at the summit ; aperture 

 lateral. Animal, body oblong, trans- 

 parent, enclosed in the shell ; head 

 having two eyes and two retractile 

 tentacula. — 5 species recent. 



This singular shell is as trans- 

 parent as glass. It is found in the 

 Mediterranean and Indian seas. 



6. Pneumodeemon. — No shell. Animal, 

 body oblong, head distinct ; tentacula placed 

 on each side the mouth ; no eyes. — 3 spe- 

 cies. 



Found in the Atlantic Ocean and the seas of 

 Amboyna. 



