4, CRETACEOUS GASTROPODA 
Conrad established for a few North American eocene species another group 
under the name of Calyptrophorus (vide Journ. Acad. Nat. Se. Phil., Vol. TV, Pl. 47, 
Figs. 21 and 29). The shell is very slightly ornamented, as in true Rostellarie, the 
spire nearly totally enveloped in a callose mass, the wing small and simple, the 
anterior canal straight and of moderate length. Calyptrophorus would seem to con- 
nect Rostellaria and Hippocrene, agreeing with the former in the form of the wing 
and canal, and with the latter in the large development of the callosity. Gabb (in his 
Catalogue, Proce. American Phil. Soc. VIII, p. 98) refers the Indian cretaceous Rost. 
palliata of Forbes to Calyptrophorus. This does not seem, however, to be fully 
justified for the present. Mr. Conrad does not show in his figures of Calyptrophorus 
any posterior canaliculation on the aperture, while in our species this is very dis- 
tinetly marked. This character is essential to all species of Rostellarie, being 
dependent upon the existence of a certain filamentous organ, somewhat similar to 
that of Oliva and allied genera. We shall notice subsequently under the descrip- 
tion of the species, that the aperture of R. palliata, Forbes, appears to have been 
anteriorly only effuse or notched, and if any canal was really present, it must have 
been very short indeed. The only very similar form, that we have been able to 
trace, is the Rostellaria levigata, Melleville (Ann. des se. geologiques ete. par 
Riviere, IT. 1843. p. 117, Pl. X, Figs. 10—11). In Melleville’s original figure 
there is apparently no sign of incompleteness of the specimen observable, although 
this seems to have been rather considerable, when we compare with it Deshayes’ 
figure in his last publication (Anim. s. vert. d. bassin de Paris, ITI, p. 460, Pl. 90, Figs. 
5and6). M. Deshayes’ representations of the single complete specimen, which he had 
obtained, named R. sublevigata, D’Orb.* shews, that the species possessed a short 
anterior canal. In any case, whether our cretaceous form had only an anterior 
notch or emargination (as is supposed in our restored figure), similar to that of 
many Pterodonte, or whether it had a short canal, which is almost quite as probable, 
there is certainly for the present no sufficient reason to separate the species generi- 
cally from the smooth fostellarie. Better materials will of course settle this 
little difference very easily. 
A number of fossil species, which are generally described under the three names 
prefixed to these notes, offer moreover a far greater difficulty than the allied forms 
* Tt seems impossible to trace this name of D’Orbieny from the “ Prodrome,” namely, from the edition 
(in three volumes) bearing date 1850-1852, and I am not aware of any other. It is true, that Sowerby designed 
in 1832 a young shell of Alaria (Rostellaria) costata (vide Stoliczka in Sitzungsb. Akad. Wien. 1865, Vol. LIT, 
Revis. p. 66), with the name R. levigata. This name was evidently selected first by Sowerby and communicated 
to Sedgwick and Murchison, who published the same in the list accompanying their paper on the “Structure 
of the Hastern Alps;” vide Trans. Geol. Soc. Lond. 2d. Ser. vol. IV, p. 419. Subsequently Mr. Sowerby changed, 
for some reason or other, this name into R. leviuscula, which is to be found in the “ Explanation of the plates” 
attached to the same volume of the Transactions. So far asI can make out, Mr. D’Orbigny was acquainted 
only with the second name of Sowerby and knew in the Prodrome no other, than Melleville’s (Deshayes ? !) 
R. levigata. I have stated elsewhere, that Sowerby’s names R. levigata and leviuscula have no signification 
in reality, and as the species, of which they are fragments, is nota Rostellaria, in the sense in which it 
appears desirable to restrict the genus, I do not know whether the change of Melleville’s original R. levigata 
is at all necessary. Certainly the reference, which Deshayes quotes in his “ Paris fossils” p. 460,—1850. Prod. 
de pal. t. IT, p. 315, No, 322,—is not to be found in that place. 
