260 SOLEN. 



the system of Linnaeus. It contains the genera Pleurotonia, 

 Rostellaria, Fusus, Pyrula, Fasciolaria, Turbinella, Columbella, 

 Triton, Murex, Ranella, and Struthiolaria. 



SIPHUNCLE. (Siphunculus.) A small siphon. 



SISTRUM. Montf. Ricinula, Auct. fig. 413. 



SKENEA. Flem. A genus including some species of Exjomphalus 

 and Cirrus. 



SMILUM. Leach. Fam. Pedunculated Cirripedes. —Descr. 

 Thirteen pieces, ten of which are in pairs, lateral, sub triangular; 

 one posterior dorsal, linear ; all smooth ; peduncle hairy. — Obs. 

 This genus is distinguished from Pentelasmis, by the number of 

 its valves, and from Scalpellum, by the hairy peduncle. S. 

 Peronii, fig. 36. 



SNAIL. The common garden Snail, so destructive to our vege- 

 tables, belongs to the genus Helix. The water snail, found in 

 ponds, is Planorbis. 



SOL. Humph. A genus consisting of several species of the 

 genus Trochus, and corresponding with the sub-genus Tubi- 

 canthus, Sw. Malac. Fig. 34 9. 



SOLARIUM. Auct. {A terrace, or gallery.) Fam. Turbinacea. 

 Lam. Goniostomata, BL— Descr. Discoidal beneath, conical 

 above, with a wide umbilicus, the spiral margin of which is 

 angulated and crenulated ; aperture trapezoidal ; peritreme thin, 

 sharp ; columella straight ; operculum horny, subspiral. — Obs. 

 The Solarium Perspectivum, is commonly called the Staircase 

 Trochus, from the angulated edges of the whorls being seen 

 through the umbilicus, which reaches to the apex, and presents 

 the appearance of a winding gallery. The species are not 

 numerous, they belong to tropical climates. A few fossil species 

 occur in the tertiary formations. Fig. 353, S. Perspectivum. 



SOLDANIA. D'Orb. A genus of microscopic Foraminifera. 



SOLEN. Auct. (J kind of shell-fish, Plin.) Fam. Solenacea, 

 Lam. Pyloridea, Bl. — Descr. Bivalve, transversely elongated, 

 sub-cylindrical, equivalve, very inequilateral, gaping at both 

 extremities, umbones terminal, close to the anterior extremity ; 



