322 Mr. C. A. Lesueur's Descriptions 



sienna.— This species is found only within the cavities of rocks, 

 which are generally covered with viva: and other marine plants, 

 at the island of St. Bartholomew. Length 2 inches 5 lines, 

 breadth 1 inch and a half. 



3. A. albeola. Body subpyriform, more inflated above, 

 terminating in two apertures, that of the branchia rather more 

 elevated ; base destitute of a peduncle, but spreading a little 

 outwards to increase the surface of attachment ; colour white, 

 diaphanous, exhibiting an interior globular, red, point. This 

 species being small, measuring but a single line in height, 

 presented less obvious characters than the preceding species; 

 it is gregarious, attached to the surface of rocks, upright, 

 and pi-esents a peculiar aspect, which at once distinguishes it 

 from any of the other species described in this paper; it may 

 possibly be the young of a larger species. — Inhabits Guada- 

 loupe. 



4. A. multiformis. Body variable in form, sometimes de- 



{>ressed or orbicular; sometimes elongated and projecting two 

 ong unequal tubes, which, as in the other species, are di- 

 stant when collapsed, and divergent when projected ; the open- 

 ing of one of these is furnished with four, and of the other 

 with five, triangular lips; base sessile, discoidal, forming an 

 attaching surface wider than the body; substance soft, dia- 

 phanous and tinted with red ; length about 5 lines, breadth 

 2 lines. — Many specimens are much smaller than the size here 

 indicated ; but whether or not these are young, or varieties, 

 can only be determined by a series of regular and constant 

 observations. Like the preceding they are gregarious, at- 

 taching themselves to rocks on the shore of the island of Gua- 

 daloupe. 



Var. «. Differs in being much larger, more solid and more 

 opaque ; the apertures are entire ; the interior of the opening 

 is black, and the general exterior colour, gray; the almost 

 smooth surface is interrupted by a few wrinkles ; it was found 

 covered with ulvte, and resembled a beautiful green Lycopo- 

 diuni; the foot was less dilated than that of the species; the 

 apertures are terminal, conic, divergent, sometimes rectilinear 

 and sometimes recurved. — It is a native of the coast of Gua- 

 dalupe. 



5. A. variabilis. Body variable in form, oblong, sessile; 

 base inflated and adherent to extraneous bodies ; apertures 

 large, distant, deep red, with five brighter spots within, and 

 each placed upon a conic protuberance, with their margins 

 haidly divided as in the other species by four or five valves; 

 the conic protuberances are unequal, the surface in common 

 with that of the whole body is rugous, of a grayish colour in 



some, 



