SUB-MYTILACEA. 267 



that of Cyclostoma. It is the Ferussina of Grateloup. Fig. 

 534, 5, 6. 



STRUTHIOLARIA. Auct. (Struthio, an Ostrich.) Fam. Canali- 

 fera, Lam. — Descr. Oblong, turrit ed, thick ; spire turrited, 

 composed of several angulated whorls ; aperture oval, sub-quad- 

 rate, oblique; outer lip thickened, reflected, advancing in the centre, 

 receding towards the extremities ; inner lip thickened, expanded 

 over the columella and part of the body whorl. — Obs. This singular 

 genus, consisting of three or four recent species, is named " Pied 

 D'Autruche" by the French, on account of some resemblance in 

 the outer lip to the foot of the Ostrich. From New Zealand. Fig, 

 39 h, S. straminea. 



STYLIFER. Brod. (Stylus, a style ; fero, to bear.)— Descr. 

 Thin, pellucid, turbinated ; apex a little out of the perpendicular; 

 aperture wide anteriorly, gradually narrowing towards the spiral 

 extremity, where it terminates acutely. — Obs. This is a genus of 

 small, transparent shells, found burrowing in the rays of Starfish. 

 There are but two or three species at present known, one of 

 which is elongated like Terebra, the other nearly globular. Fig. 

 12, S. astericola. West Indies, Gallapagos, and Britain. 



STYLINA. Fleni. Stylifer, Brod. 



SUB. {under.) Used as a prefix and signifying nearly. Thus a 

 bivalve-shell, the valves of which are nearly alike, would be de- 

 scribed as SM&equivalve. 



SUB-APLYSIACEA. Bl. The first family of the order Mono- 

 pleurobranchiata, Bl. containing several genera of Mollusca without 

 shells, and the genus Pleurobranchus. 



SUB-BIVALVES. A term of distinction applied by De Blainville, 

 to those spiral univalves which have an operculum ; these, as 

 they constitute two distinct pieces, he considers as forming a 

 medium between univalves and bivalves. 



SUB-MYTILACEA. Bl. The sixth family of the order Lamelli- 

 branchiata, Bl. the shells belonging to which are described as 

 free, rather pearly, regular, equivalve ; hinge dorsal, laminated ; 

 ligament external ; two muscular impressions; palleal impresion 

 not sinuated. This family, with the exception of the last genus, 



