STOMATIA, MOLLUSCA, -49 



H. tuberculala, Lin. Shell subovate, depressed, longitudinally stri- 

 ated and transversely plicated ; the wrinkles unequal, remote ; 

 spire prominent ; marginal ridge with about twenty-eight tu- 

 bercles, increasing in size as they recede from the summit, and 

 from six to eight of the lowermost peforated; colour reddish brown, 

 more or less mottled ; inside pearly. 3 or 4 inches long. Inha- 

 bits coasts of Europe. B. Brown's Illust. pi. 36, fig. 2, 18. 



Gen. 51. STOMATIA, Lam. 



Shell auriform, imperforate, with prominent spire ; aperture en- 

 tire, large, longer than broad, the right margin as elevated 

 as the pillar ; a transverse and tubercular rib on the back. 



S. phymotis, Lam. Shell ear-shaped, ovate, oblong ; back convex, 

 striated, nodulous, silvery ; spire small ; lip thin, acute. 7 lines 

 long. Inhabits Indian seas. -Cte. x. pi. 166, fig. 1600, 1601. 



Gen. 52. STOMATELLA, Lam. 



Shell orbicular or oblong, auriform, imperforate ; aperture en- 

 tire, large, longer than broad, right margin widened, dilated, 

 open. 



The shells of this genus are marine, and silvery within. 



S. imbricata, Lam. Shell suborbicular, convex, depressed, rough- 

 ish, with crowded transverse scaly imbricated furrows ; spire ex- 

 serted ; colour gray. 17 lines long. Indian seas. Lam. vi. 209. 



S. auricula, Lam. (Patella lutea, Lin.) Shell auriform, ovate ob- 

 long ; back convex, smooth, yellow rose-coloured, with fuscous lines ; 

 spire lateral, pointed ; iridescent within. 9 lines long. Inhabits 

 seas of new Holland. Rumph. Mus. pi. 40, fig. I. 



Gen. 53. SIGARETUS, Lam. Helix, Lin. 

 Shell subauriform, almost orbicular, with the left border short 

 and in a spiral form ; aperture entire, very wide, longer than 

 broad, the margins disunited. 



The shell of this genus is concealed in the mantle of the animal, and it seems at 

 first sight to have no shell. 



S. haliotoideus, Lam. Shell auriform, imperforate, depressed, with 

 undulated striae, and the spire flat ; aperture oval, very large, and 

 exposing the whole inside. 13 lines long. Inhabits Mediter- 

 ranean and Atlantic seas. Petiv. Gaz. pi. 12, fig. 4. 



FAMILY V. JANTHINIA. 

 Gen. 54. JANTHINA, Lam. Helix, Lin. 

 Shell gibbous, conoidal, thin, transparent; aperture triangular; 

 columella straight, surpassing the base of the right margin ; 

 no operculum. 



The Janthinae are marine shells, which are never met with but at the surface of 

 the water. The shell is violet-coloured, very thin, transparent and fragile ; and the 

 animal floats suspended at the surface by a vesicular appendage, which adheres to its 

 foot. 



J. communis, Lam. (H. Janthina, Lin.) Shell nearly imperforate, 



VOL. II. D 



