196 HALF AN HOUR WITH SHELL-FISH. 



The JEolis has a frilled scroll, arranged spirally. 

 When minutely examined these ribbons are seen to 

 consist of rows of eggs, imbedded in a clear jelly- 

 looking substance. The j?Eolis brings forth an 

 enormous number of these eggs, frequently not less 

 than a quarter of a million in a year. Space forbids 

 us noticing other than the typical and commonest 

 of the nudibranch mollusca, there being a great 

 number living even in our British seas. 



As regards the true univalves, it is necessary to 

 look keenly out for specimens; for our English 

 species do not equal in size those of tropical seas. 

 Most of them are very minute, and only to be found 

 after much searching under stones, in mud, among 

 sea-weeds, &c. But the morning after a storm ought 

 never to be missed being turned to advantage, for 

 that is the only opportunity of obtaining the deeper 

 water species, except the student has the opportunity 

 of dredging, or manages to arrange with the trawl- 

 fishers to save him those they scrape up from the 

 deep sea-bottom. On the rocks and stones the com- 

 monest objects are the limpets and the periwinkles. 

 The former we have already referred to, and its 

 appearance is undoubtedly well known to the 

 majority of our readers. It is seen to the best 

 advantage when placed in the aquarium ; although, 

 unfortunately, it does not live long there, for some 

 cause or another. Only there will you have a chance 

 of observing its head and tentacles, for it is a very 

 sensitive and cautious animal. The " tooth-ribbon " 



