150 THE HALL OF SHELLS. 
There is another species which excels as a 
swimmer. Expanding quickly the lobes of its 
foot, it strikes the water suddenly with these 
and darts swiftly away in sportive fashion 
through the waves, or speeds at will from one 
sandy shoal to another. 
Belonging to a subfamily of the Olividee 
we find the harp shell, to which Miss Bremely 
referred as fitting to furnish the accompani- 
ments to sea songs, which she fancied to be en- 
eraven upon the pretty olives. These harp 
shells are in truth beautiful enough to be sug- 
gestive of conceptions of harmony, of music, 
and of delight to sea nymphs and “ ocean 
swells.” The shells are prominently ribbed, and 
decorated with well-defined dark lines of inter- 
costal painting. Most of them are highly col- 
ored, banded, and festooned in the richest man- 
ner. Harpa ventricosa and Harpa articularis 
are among the most beautiful. 
Unlike some other beauties the Harpinze 
all appear to delight im their large feet. So 
large are they in fact that their possessors are 
unable to accommodate them to their shells ; 
so after the fashion of Cinderella’s wicked sis- 
ters, who “would not need to walk when they 
were queens,” they are said to detach a portion 
of the foot in emergencies. 
