SCALARIA. MOLLUSCA. 47 



D. laciniata, Lam. ( T. delphmus, Lin.) Shell depressed and fo- 

 liated ; umbilicus large, armed with small vaulted scales in spi- 

 ral rows ; colour blackish brown, red, or yellowish, variegated 

 with white. 1^ inch long. Indian seas Lister, pi. 608, fig. 45. 

 Several fossil species of this genus have been found in Britain, in the lower oolite, 



and carboniferous limestone. 



Gen. 46. SCALARIA, Lam. Turbo, Lin. 

 Shell subturreted, with longitudinal, elevated, edged, interrupt- 

 ed ribs ; aperture nearly round, the margins united circular- 

 ly, and terminated by a thin reflected ridge. 



The spire of this genus is more or less elongated, according to the species ; but 

 in all that are known the lower whorl is largest. Some species have the whorls en- 

 tirely separated like the turns of a screw. The animal inhabitant has two tenta- 

 cula, terminating in a setaceous filament. The eyes are situate at the base of these 

 filaments. 



S. pretiosa, Lam. ( T. scalaris, Lin.) The Wentletrap. Shell 

 conical, umbilicated, with the whorls of the spire detached, smooth, 

 connected by longitudinal ribs, the last turn ventricose. 1^ inch 

 long. Inhabits Indian seas. D'Argenv. pi. 11, fig. V. 

 This valuable and elegant shell is about an inch and a half or two inches long, 

 and the breadth is about three-fifths of the length. It has eight subcylindrical whorls, 

 which, without being attached to each other, are connected only by elevated some- 

 what membranous longitudinal ribs, and of these there are about eight on the body 

 whorl. The shell is generally snow-white or pale flesh-colour. Large and perfect 

 specimens formerly sold for very high prices. One in Bullock's Museum was valued 

 at two hundred guineas ; and Da Costa mentions a sale at which four specimens sold 

 at from sixteen to twenty-three pounds each. 



S. communis, Lam. ( T. clathrus, Lin.) Shell turreted, imperforate, 

 white or pale yellow, with rounded subcontiguous whorls, and 

 thick longitudinal distant ribs. 1 J inch long. Inhabits coasts of 

 Europe and America. B. Browns Illust. pi. 51, fig. 13. 



Gen. 47. VERMETUS, Lam. 



Shell thin, tubular, of a loose spiral form, fixed to other bodies 

 by the apex of the spire ; aperture orbicular, with the mar- 

 gin united ; an operculum. 



These shells are generally found in groups, and as if twisted together. The ani- 

 mal, according to Adanson, is vermiform, with a truncated head and two tentacula, 

 with eyes at their base ; a cylindrical foot, incapable of crawling, below the head, 

 with a cartilaginous operculum ; two filaments at the base of the head, and the man- 

 tle surrounding the exterior of the shell. 



V. lumbricalis, Lam. Shell fixed by the apex of the spire ; the 

 tube ascending, slender pellucid, reddish yellow. Inhabits Afri- 

 can seas. Lam. vi. 2. 225. 



FAMILY ILL PLICACEA. 

 Shell with the aperture not widened, and folds on the columella. 



Gen. 48. PYRAMIDELLA, Lam. Trochus, Lin. 

 Shell turreted, destitute of epidermis ; aperture entire, semioval, 

 the exterior margin edged ; columella straight, projecting in- 



