LAMP-SHELLS AND THEIR ALLIES 



17 



on its side you can readily see 

 why these shells have been com- 

 pared to the ancient lamps, such 

 as are dug out of the ruins of 

 Pompeii and other Roman cities. 

 The large valve of the shell an- 

 swers to the bowl ot the lamp, 

 and at the end is a small hole as 

 if for the wick. Through this 

 hole really runs a strong stem, 

 by which the animal is firmly at- 

 tached to the rock or some other Fig. 7 

 anchorage. The hole in this shell, however, is very 

 small when compared with that shown in the last 

 figure. The color is reddish, at least in large speci- 

 mens, though some of the little ones are brown. 

 Rich markings of a deeper color sometimes seem to 

 show through the shell. Most of the specimens are 

 obtained by dredging or from fishermen's nets, and 

 sometimes a whole cluster is pulled up, all of them 

 attached to some old shell, and looking like a bunch 

 of plums. They are mostly collected in the vicinity 

 of the Santa Barbara Channel, though they extend 

 northward at least to Monterey Bay. 



Laqueus jeffreysi, Dall, Jeffrey's Lamp-shell, re- 

 sembles the last species, but lacks the rich, warm, 

 reddish tints. The shell is heavier, browner, and 

 the foramen, or opening, is larger. It is found 

 farther to the north, and was once called the Van- 

 couver variety of the last species. They exist side 

 by side, however, off the coast of California. 



Frieleia halli^ Dall, the Parrot Lamp-shell, is a 



