282 



Shell Life 



Spawn of Doris 



Young of Doris, 

 with shell 



cliondria panicea, that form large patches on our 

 rocks at low water and below, and upon which the 



Sea Lemon chiefly 

 feeds, equally vary 

 in tint. Where 

 this Halichondria 

 or Crumb-of-bread 

 Sponge grows the 

 Sea Lemon may 

 also be found, and 

 when the slug has 

 moved away from the sj^onge the former becomes a 

 very conspicuous object, but when upon or beside it 

 the slug has every possible chance of escaping notice. 

 Its back is the same colour as the sponge, and the 

 numerous little warts help the resemblance. The 

 circle of gill - plumes resembles the oscidum of the 

 sponge. Not far off in spring we are almost sure to 

 find the remarkable egg-ribbon, of which each indi- 

 vidual produces two or three each year. 

 It is a ribbon 9 or 10 inches long: and 

 1 inch broad, with waved free edo^e, the 

 other being glued to the rock as de- 

 posited and coiled in a spiral. Each 

 ribbon is estimated to contain on an 

 averao^e 50,000 ova. There are eio^ht 

 other members of this genus, differing 

 in size, colour, and other points. One 

 of these, the Eed Doris (D. coccinea), 

 is figured. It is only about 1 inch long, 

 is of a bright scarlet colour, dotted 

 with black. It occurs on the Cornish coast, feeding 

 on the sponge Halichondria sanguinea, where it is 



Red Doris 



