246 LIFE, IN ITS INTERMEDIATE FORMS. 
under surface of the body being dilated into a flat mus- 
cular foot, the action of which may be observed by any 
one who chooses to look at a snail gliding up a pane of 
glass. This great muscular crawling disk is so charac- 
teristic as to have given name to the Class, Gastropoda, 
from two Greek words, signifying “ belly-footed.” 
A cabinet of shells is a beautiful and interesting sight ; 
the rich, varied, and delicate colours, the pearly iri- 
descence, the elaborate patterns, the porcellaneous texture, 
the perfect polish, the exquisite sculpture, and the grace- 
ful forms which we see profusely displayed there, must 
always delight the eye. No won- 
der that the conchologist regards 
his treasures, the spoils of every 
sea and every shore, as “ an as- 
semblage of gems,” and that he 
delights to exhibit them as les de- 
l-ices des yeux et de V esprit. The 
prices that have sometimes been 
given for rare or beautiful speci- 
mens would be considered fabu- 
lous, wei'o they not capable of in- 
dubitable proof. “ In 1753, at 
the sale of Commodore Lisle’s shells, at Longford’s, four 
Wentletraps ( Scalaria pretiosa) were sold for seventy-five 
pounds twelve shillings, viz., — one not quite perfect for 
sixteen guineas ; a very fine and perfect one for eighteen 
guineas ; another for sixteen guineas ; and a fourth for 
twenty-three pounds two shillings.” 
But higher prices than these have been given. That in 
Mr Bullock’s Museum, supposed to be the largest known, 
Wontletmp. 
