166 CLASS III. GASTEROPODA. ORDER VII. PECTINIBRANCHIATA. 
Pl. CCXVIII. Fig. 15. 
Trocuus Javanicus, Lamarck, Anim. sans vert., vol. vil. p.25. Deles- 
sert, Recueil de Coquilles, pl. 35. f. 2. a, 6. 
Pl. CCXVIII. Fig. 16. 
Trocuus MEeLaNnostoma, Nobis, Proceedings Zool. Soc., 1842. 
Pl. CCXVIII. Fig. 17. 
Trocuus Guitprorpia, Nobis. 
Imperator Guildfordie*, Gray, MSS. British Museum. 
TURBO, Linneus. 
Testa turbinata, solida, intus plerumque vel argenteo-, vel aureo-margari- 
tacea, anfractibus convexis, nunquam depressis, extus aut rugosa, 
aut glabra; apertura rotunda, columella arcuatd, planulata, non 
truncata ; marginibus disjunctis, labro seu simplici, seu denticulato. 
Operculum nunc corneum, nunc calcareum. 
Our observations on the preceding genus apply so fully to the present, 
that little need be added. The genus Turbo was introduced by Linnzus, 
and has been from time to time divested of the Delphinule, the Scalaria, 
the Littorine, the Turritelle, the Cyclostomata, and a few others. The 
Turbines having for the most part a much larger and more solid shell 
than the Trochi, the operculum is generally calcareous. 
The shell of Turbo, which is sometimes highly polished, sometimes 
covered with a thick periostraca, may be described as being turbinated, 
and generally pearly within ; the whorls are convex and never depressed ; 
the aperture is round, and the columella is curved, flattish, and not trun- 
* As the greater part of Mr. Gray’s species are known only in manuscript, we gladly em- 
brace the opportunity of giving a very excellent one publicity. 
