TRACHELIPODA. 



Genus 51 —STOMA.TlA.— Lamarck. 



Generic Character. — Shell ear-shaped, imperforate ; spire 

 prominent ; aperture entire, oblong, and large ; outer lip 

 elevated as much as the pillar ; back with a transverse sub- 

 carinated tuberculated rib. 



Stomatia phymotls. — The Tumoured St^matia. Plate 

 XIL fig. 29. Ovate oblong ; back convex, striated, nodu- 

 lous, and vi^hite ; spire small, contorted ; lip thin and acute. 

 Three and a fourth inches long. Inhabits the Indian ocean. 



Ge«Ms 52.— STOxMATELL A.— ZamarcA. 



Generic Character. — Shell orbicular or oblong, ear-shaped, 

 imperforate ; aperture entire, large, elongated ; outer lip 

 effuse, dilated, and open. 



This shell is distinguished from Stomatia, by its never having the 

 transverse rib of the species of that genus. 



Stomatella imbricata. — The Imbricated Stomatella. 

 Plate XII. fig. 30. Suborbicular, convex, somewhat de- 

 pressed, rough, having thick-set transverse ribs, covered 

 with imbricated scales ; grayish-brown. More than an inch 

 and a half long. Inhabits the Indian ocean. 



Genus 53.— SIGARETUS.— Zawarc^. 



Generic Character. — Shell subauriform, suborbicular ; 

 outer lip short and spirally intorted ; aperture entire, very 

 expanded, ovate oblong ; the margins disunited. 



Sigaretus somewhat approximates the genus Natica, and much re- 

 sembles a depressed shell of that genus, from which, however, the 

 extraordinai-y width of the aperture, and its spiral short columella 

 render it quite distinct. 



Sigaretus concavus. — The Concave Sigaretus. Plate 

 XII. fig. 25. Ovate, back convex, covered with transverse 

 undulated striae ; reddish-yellow, spire white, somewhat 

 prominent; aperture expanded, concave; umbilicus deepish. 

 Inhabits the Indian ocean. 



