188 CRETACEOUS GASTROPODA 
or still less of the Gosau Rostellaria depressa, Zek. (Abhand. Geol. Reichs-Anst. 1852, 
Vol. I, Pt. IL, Pl. XIII, Fig. 2). Our Cerith. detectwm, n. sp. may be another 
eretaceous form, belonging to this group. The Cerith. Oassendii and Nostradami, 
Coquand (Etage Aptien de l’ Espagne, 1866, Pl. IV, Figs. 14, 15, 16), are probably 
true Fibule. 
1. a.—With these chiefly smooth species there are others connected, which agree 
with them in form, but have usually a row of strong tubercles along the posteridr 
suture; the tubercles being produced by a kind of insinuation in this place on the 
outer lip. We refer here to the jurassic Cerith. margaritiferum, Piette, ( ? d’Arch. ; 
Bull. Soc. Géol. France. 2me. ser. XIV, p. 555, Pl. VI, Figs. 1—3), or the cretaceous 
Cerith. hispidum, Zek. (Abhand. Geol. Reichs-Anst. 1852, Vol. I, Pt. IT, Pl. XXTV, 
Figs, 1, 2, 6, 7), which I referred to Vertagus (Sitz. Akad. Wien, 1865, LII, Rev. 
etc. p. 110), because it has a columellar fold, although it must be conceded, that the 
form does not agree very much with recent species of Vertagus. We describe two 
other very similar forms from South India, namely, Cerith, hispidulum and inaugu- 
ratum, i. Sp. 
The eocene Cerith. gigantewm belongs to this same group of species. 
1. 6.—A third series of very remarkable forms of Cerithiwm are principally 
eretaceous; they are distinguished by a remarkably striking resemblance to 
Nerinee, great thickness of the shell, and transversally coarsely ribbed or tuber- 
culated whorls. I mean under this section species like Cerith. Haidingeri, Zekeli 
(1. c. Pl. XXIV, Figs. 3, 4, 5, 8, 9), from the Alpine Gosau-deposits, or Cerith. Sturt, 
Stoliczka (Jahrb. Geol. Reichs-Anst. 1863, Vol. XIII, p. 50, Fig. 4), and others. 
The sole representative of all these fossil forms among recent shells appears 
to be Cerith. leve, Quoy and Gaim. (Voy. Astrolabe, Vol. IIT, p. 106, Atlas Pl. 54, 
Figs. 1—3). Itis astonishing to find this species placed by the late L. Reeve 
(Conch. Icon. 1866) in Zelescopium. The author had evidently not referred to the 
original figure of the species in the Atlas of the ‘ Astrolabe’, otherwise he would 
have found in Fig. 8 a representation of a paucispiral operculum, such as he 
had occasion to observe on Mr. Hanley’s specimen. Quoy and Gaimard state, that 
they found the species at the entrance into King-George’s Sound, South Australia. 
2.  ustoma, Piette, 1855 (Bull. Soc. Geol. France, 2me. ser. XII. Vol. 
p. 1107, and XIII Vol., p. 99, Pl. II, Figs. 8—11), has been proposed for a jurassic 
turreted species with an ornamentation like the doubtful /%dw/e mentioned 
in la (vide Cerith. hispidulum un. sp.), but both the margins of the aper- 
ture are much expanded and posteriorly united by an indistinct canal. The con- 
siderable expansion of the inner lip distinguishes this form from oséellaria, and 
the ornamentation of the shells agrees undoubtedly better with the Currrmirm2z, 
on which account we would prefer to classify this genus here. Besides the Lwsé. 
tuberculosa, Piette, another jurassic species, the Cerith. rostellaria, Buvignier (Stat. 
d. 1. Meuse, Pl. XXVII, Figs. 7—9), and probably the triassic Cerith. Donati, 
Stoppani (Pal. Lomb. 3me. ser. Pl. XXVIII, Figs. 14 and 15), belong to this genus. 
We are not aware that any cretaceous species of Hustoma have been reported. 
