6 MULTIVALVES LEl'AS. 



Other species possess the intermediate gradations 

 of number, as far as twenty-four, which is not un- 

 frequent in the L. pollicipes. — The valves, of what- 

 ever number they consist, are variously diversified 

 with strife, ridges, and grooves. The striie are 

 mostly transverse; the ridges, on the contrary, are 

 longitudinal, and not uncommonly beset with rough 

 projections and acute spines, as in the L. spinosa. 



The valves which compose the operculum, or lid, 

 often vary in their number and shape; in some they 

 only consist of two; in others, of three or four; and 

 sometimes of a far greater number. They are usually 

 attached to a ligament, and occasionally present an 

 acute form, while in other species they are perfectly 

 obtuse. 



The color also differs considerably, though the most 

 usual is of a bluish, purplish, or reddish cast ; some 

 are variegated with black and green, and others are 

 greyish-white, as the L. mitella, &c. 



The Lepades are never found detached, but always 

 fixed by the base or stalk to other bodies; they adhere in 

 clusters to rocks, and often form groups on shells, loose 

 stones, anchors, &c. ; they are also found on marine ani- 

 mals, as the whale and the turtle. They also affix them- 

 selves to ships, and, though at first invisible, so rapid is 

 their increase in magnitude and number, that the veloci- 

 ty of a vessel is considerably impeded by them. This 

 seems to imply that^he animal exists in the sea in 

 the state of animalcula. 



The interior of some species of this genus is a hollow 

 tube, but in others it is divided into separate compart- 



