284 STKOMBTJS. 



variegated without, irrideseent within ; spire depressed ; aperture 

 entire, very wide, oblique ; peritreme uninterrupted. — Obs. 

 This genus is known from Haliotis by being destitute of the 

 series of holes ; is distinguished from Sigaretus by the substance 

 of the shell, the latter being internal, and never pearly. Our 

 description includes Stomatella, Lam. The Stomatiae are 

 marine, and belong to the East Indies and New Holland. 

 S. Phymotis. PI. xv. fig. 335. 



STEEPHONA. Brown, 1756. Olivia, Lamarck. 



STOEILLTJS. Montf. 1, 131. A genus of microscopic Eorami- 

 nifera, included in the genus Eotallites in M. De. Blainville's 

 system. 



STEAPAEOLLUS. Montf. A genus containing some species of 

 Helix, Auct. G-eneric characters not defined. 



STEEPTAXIS. Gray. Fam. Colimacea, limx.—Descr. Ovate, 

 or oblong ; when young, sub-hemispherical, deeply umbilicated, 

 with rapidly enlarging whorls. At length the penultimate 

 whorl is bent towards the right and dorsal side of the axis, and 

 the umbilicus becomes depressed, and often nearly closed. The 

 mouth is lunulate, the edge slightly thickened and reflected, and 

 often vrith a single tooth on the outer side of the inner lip, — 

 Obs. This genus of land shells is separated from Helix on 

 account of the eccentricity of the penultimate whorl. S. contusa, 

 PI. xiii. fig. 269, 270. 



STEIATED. (Stria, a groove.) Marked with fine grooves or lines. 



STEIGOCEPHALUS. Defr. Peftamertjs, Sow. ? Gtpidia. 

 Dalman. 



STEOMBUS. Auct. Fam. Alatse, Lam. Angiostomata, Bl. — 

 Descr. Oblong, turrited, rather ventricose, solid ; aperture 

 generally lengthened, terminating posteriorly in a short canal, 

 and anteriorly in an emargination or truncated canal ; outer 

 lip, when young, thin; when fuU grovsm, thickened and expanded, 

 lobed at the spiral extremity, sinuated anteriorly, near the 

 caudal canal. Obs. This well known genus includes some species 

 of immense size, commonly called conch shells. Most of the 

 recent species are brought from the Indian Ocean. Very few 

 fossil species are known. The young shells have very much the 



