The Shell-bearing Sea Slugs 



body. Length, A inch. It is found well concealed on mossy 

 rocks on Southern California coast. 



Thin, handsomely banded bubble shells, partially internal, 

 are included in genus Aplustrum and a sub-genus, Hydatina. 



THE SEA HARES 



Family ApLYSiiOit 



Genus APLYSIA, Linn. 



I met a sea hare first on the border of a coral key in southern 

 Florida. The strange-looking object was about six inches long, 

 a mass of mottled purple jelly, tapering to a point behind, extend- 

 ing forward into a small, erect head on a long neck. Two pointed 

 wing-like flaps met over the back. Two flexible prongs stood 

 out from the head and two smaller one from the neck. The 

 creature swam gracefully among the seaweeds, using as propellers 

 the broad side flaps. 1 ventured to capture this interesting 

 stranger in a crab net, whereupon the surrounding water was 

 dyed purple in an instant. 



This is a reasonable defence of an animal whose shell is 

 nothing but a transparent, flexible rudimentary plate, hidden 

 in the soft back. Under the shell is the gill, to which water is 

 brought by a siphonal fold of the mantle. The head is like a 

 hare's, when seen in front. 



At different ages the sea hare lives at different depths, 

 closely imitating in colour the seaweeds and anemones upon 

 which it feeds. When adult it has passed through several zones, 

 and takes the liberty of ranging backward to shallower water. 

 At breeding time the creatures flock together. The eggs are laid 

 among seaweeds in gelatinous, thread-like cases. 



The name Aplysia means indelible. The fluid emitted was 

 once believed to be a poison, killing even the person who touched 

 the animal with a stick. The Mediterranean A. depilans was 

 charged with causing baldness, by a form of absent treatment. 

 It is known now that they are all harmless creatures; the natives 

 of the Friendly and Society Islands use kindred species for food, 

 preferring to eat them raw. 



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