430 THE OCEAN WORLD. 
larger as well as more numerous and much richer in colour in 
equatorial seas, and especially in the southern hemisphere, than in 
European seas. They attain, in fact, their maximum of develop- 
Fig. 211.—Patella ceerulea (Lamarck). Fig. 212.—Patella umbella (Gmel.) 
ment there ; for in the Straits of Magellan species are found as large 
as a slop-basin, which the natives use for culinary purposes. 
The common limpet is thick, solid, oval, and nearly circular, 
generally conical, and covered with a great number of very fine 
Fig. 213.—Patella granatina (Linnzeus). Fig. 214.—Patella barbata (Lamarck). 
stripes. Its colour is of a greenish grey, uniform above, and of a 
greenish yellow inside. It is abundant in the Channel and on 
Atlantic coasts. 
The blue limpet, Patella cerulea (Fig. 211), from St. Helena, 
has an oval shell, broadest behind, moderately thick, depressed, 
