The Shell-bearing Sea Slugs 



Atys Naucum is a pure white bubble-like shell in this 

 family. 



LATHE SHELLS 



Family Tornatinid^ 

 Genus TORNATINA, A. Ads. 



Shell thin, inflated, cylindrical, entirely covering the animal. 

 The spire is concealed, as in Cypraea. The head and foot are 

 split; the halves are reflected over the shell. The radula is 

 replaced by a powerful gizzard in which molluscan food is ground. 

 So solid and compactly built do these sheHs seem that to Linnaeus 

 they looked as if turned on a lathe, hence the name. 



T. punctistriata, Ads., a minute representative of this 

 genus, occurs from New York to Massachusetts. 



THE BUBBLE SHELLS 



Family BuLLiDy^ 

 Genus BULLA, Linn. 



Shell thin, smooth, ventricose, almost globular; spire pol- 

 ished, deeply pitted; lip plain; body large, fleshy, partially 

 enveloping the shell by reflexing the two wing-like parapodia. 

 Eyes prominent on frontal disc. Quantities of mucus are se- 

 creted by the skin to keep it moist while the tide is out. 



The food of Bulla is molluscan; the creature burrows in the 

 sandy mud and captures small bivalves and snails which it swal- 

 lows whole and grinds to fragments between the strong walls 

 of the gizzard. The mantle flaps are used in swimming. 



The Cloudy Bubble Shell (B. nehuhsa, Gld., B. Gouldiana, 

 Pils.) 1 have often found on the mud flats of San Pedro, and 

 watched the captive slowly stow away the viscid bulk of its great 

 foot within the ample shell. I have washed away the slimy mud, 

 and admired the cloudy splotching of yellow and brown on its 



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