THE CYMBULIA. 343 



A good example of the Pteropoda is the large-winged Cymbulia. Though greatly 

 resembling the oarinaria in general appearance, it is divided from that creature by many 



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WING-FOOTEU MOLLTTSK.— Pteropoda. 



important structural differences. Its shell is flexible, and in shape and translucency somewhat 

 like the glass-slipper of fairy mythology, the point, or toe, being set forward. Only three 

 species of this genus are known. 



