364 CRETACEOUS GASTROPODA 
The only cretaceous species which probably belongs to this genus is Turbo plicatilis, Desh. 
(d’Orbigny, Pal. franc. terr. crét. II, pl. 188, figs. 11-13). Zr. crucianus, P. and C., which I have 
mentioned under Huchelus, has also the general form of the recent Chlorostoma, but not the thickened 
lip, and the tooth is rather median than terminal. 3 
12. Trochocochlea, Klein, 1757 (Ostrac. p. 42, pl. 2, figs. 53-54;—H. and 
A. Adams’ Gen. I, p. 425—Osilinus, Phil., Handb., p. 210—Zabio apud Gray, Cat. 
1857, p. 155). Shell ovately conical, solid, smooth or spirally ridged, not umbili- 
cated, but with the inner lip flattened, concave anteriorly, provided with a tooth at 
the termination of the columella. Klein’s figures of two species are very character- 
istic and entitle his name to priority. 
This is a very important genus in fossil Conchology ; numerous jurassic species belong to it, 
like Turbo bicinctus, dOrb., 7. castor, d’Orb., Trockh. Pietti, Heb. et Desl., Monod. Lyelli and formosa, 
Morris and Lycett, U. comma, M. Waltoni, M. tegulata, M. arata of Lycett and many others. 
Of cretaceous species I may mention Trochus Marollinus, d’Orb., and 7. Dupperreyi, @ Arch. 
18. Tegula, Lesson, 1832, is considered by Gray (Cat. 1857, p. 153) and 
others as a distinct genus. The type is 7. pellis-serpentis, which is not only 
distinguished by its more pyramidal form and granulated whorls, but especially 
by a broad callosity covering the concave umbilical region; the columella is twisted 
and terminates with an obtuse point. 
14. Livona, Gray, 1842 (H. and A. Adams, Gen. I, p. 412,—Cittarium, Phil., 
184.7, Handb. p. 210); the type is Turbo pica, Linn., which is specially characterized 
by a toothlike process at the entrance of the umbilicus; the shell is broadly 
conical, solid, smooth ; aperture roundish with the margins single, the outer one 
sharpened on the edge. 
b. Sub-family,—TROCHIN 41. 
Shell pyramidal or subturreted, columellar lip anteriorly truncated, base of shell 
flattened or concave. 
15. Carinidea, Swainson, 1840 (Infundibulum, apud H. and A. Adams, 
Gen. I, p. 415;—TZrochus, ex parte in Gray’s Cat. 1857, p. 148 ;—Polydonta 
ex parte in Philippi’s Handb., p. 209). The type of this genus is Troch. concavus 
of Linné, having the periphery of the last whorl strongly carinated, somewhat 
similar to XYenophora or Infundibulum; the base is strongly concave, the inner 
lip generally smooth and anteriorly very slightly obtuse, passing gradually into 
the outer lip. I have already (p. 316) remarked that the name Infundibulum, 
Montf., cannot be applied to this group of shells, but at the same time I believe 
that they ought to be generically distinguished from Polydonta, being more closely 
allied to the next genus. Trochus Hammon, Coquand (Const., pl. 2, fig. 9) from 
the cretaceous rocks of Algiers may belong to this genus. 
16. Trochus, Linné, 1758 (H. and A. Adams, Gen. I, p. 412) as restricted for 
the species with a smooth, slightly bent inner lip, being posteriorly twisted and 
terminating anteriorly obtusely, but not being sensibly thickened; base concave in 
the centre, but not umbilicated. 
