22 MULTI VALVES. LEPAS. 



t:uum, but in otliers it is either filled up with tubular 

 pores, as in the Lepas porosa, or divided into separate 

 compartments or chambers. 



Notwithstanding the great affinity that exists through- 

 out the Lepas tribe, there are a few exceptionable spe- 

 cies, in which a resemblance is difficult to be traced; as, 

 for example, the L.scalpellum, L. anserifera, L. anatifera, 

 and varieties emanating from them. 



These species are closely allied to each other, but ex- 

 ceedingly dissimilar to the rest of their genus; for the 

 generality of Lepades are affixed to other bodies or sub- 

 stances by the base, or lower part of the shell, whereas 

 these are attached by a stalk, stem, or pedicle, which pro- 

 ceeds from the base of the shell to the substance that 

 sustains it. 



This peculiar structure engenders the idea of comparing 

 them to the form of certain dwarf plants, as the crocus, 

 and others of the like description, to which, in appear- 

 ance, they bear considerable resemblance. 



The stem by which the shells are supported, diflfers ex- 

 ceedingly in quality and substance; sometimes it appears 

 a smooth, film-like tube, of a texture finer and thinner 

 than gold-beater's skin, though somewhat lighter colored, 

 and not nnfrequently tinted with bright red or orange; 

 and often it is dark or blueish-brown, much coarser, and 

 wrinkled or granulated. 



The L. anserifera and L. anatifera, are almost invari- 

 ably composed of five valves; they are supplied with 

 beautiful feathery tentacula of a brown color, and ele* 

 gantly curled. From this circumstance, probably, they 

 were supposed to be the origin of the barnacle or brent- 

 geese, and are therefore commonly known by the name 

 of Goose-shells or duck-barnacles. The Lepas anserifera 

 is sometimes found in a fossil state. 



