3328 



THE MOLLUSKS OR SHELLFISH 



tentacles are slender, laminated, and retractile within long compressed trumpet-shaped 

 sheaths. The genus contains only a few species, but it has been found in almost 

 every sea. Phyllirhbe is a genus of Nudibranchiata remarkable for the absence of 

 both foot and gills. The body is compressed laterally, and so translucent that 

 all the internal anatomy is visible. These animals are pelagic and eminently 

 phosphorescent. Specimens kept in aquaria have been observed to be instantly 

 luminous if touched. 



jEolidia papillosa. 



In the ^Lolidiidce the body is slug-like and tapering posteriorly. There are two 

 labial and two dorsal tentacles, and the dorsal branchial papillae are cylindrical or 

 fusiform, and arranged in transverse rows on the sides of the back; the front of 

 the creeping disc is often produced on each side in the form of tentacles; the horny 

 jaws are large, and the radula consists generally of a single series of spinous plates. 



Elysia uiridis (magnified. ) 



papillosa, the largest of the British species, may be found under stones 

 between tide marks on many parts of the coasts. It is brown, gray, or orange, spotted 

 with brown or purple and white; the dorsal tentacles are brown with white tips, 

 and the papillae are speckled with brown or lilac and white, with white tips. These 

 mollusks are animal feeders, partial to sea anemones. Their fecundity is very great, 

 as many as sixty thousand eggs being deposited by a single individual at one time. 



