209 CRETACEOUS GASTROPODA 
Localities —N. HE. of Karapaudy and N. of Comarapolliam, in whitish siliceous 
sandstones ; not very common. 
Formation.—Arrialoor group. 
11. CERITHIUM FERTILE, Stoliczka. Pl. XV, Figs. 11 and 12, and Pl. XIX, Fig. 5. 
Cerith. testa conica; anfractibus paulo excavatis, spiraliter minute-striatis, antice et 
postice atque prope medium crenulate-carinatis : carina suturali posteriori muito 
fortiori, mediana minima; apertura _quadrangulari, antice canali brevi terminante; 
labio levigato ; columella contorta. 
Spiral angle about 40°; sutural angle 1°—4° 
Height of last whorl : total of shell (considered as.1:00) 5c eee 0'28 
+5 », penultimate whorl : height of spire (considered as 100) ... O15 
e 3 a ss : its width ( A So Missed eedue ORL& 
This species is one out of a large number of very similar forms known from 
the cretaceous deposits of Europe, namely, Cerith. Derignyanum, Rhodani, and 
Sabaudianum, of Pictetand Roux., Cerith. Mosense, Buvignier, Cerith. ornatissimum, 
D’Orb., Cerith. Chavannesi, Pictet and Campiche, and some others. The nearest 
allies are certainly Cerith. Mosense and ornatissimum, which are stated by Pictet to 
be undoubtedly different species (vide Mat. p. 1. Pal. Suisse, ser. III, p. 294). From 
both these, certainly very similar species, our Indian fossil differs by a greater 
height of the whorls as compared: with their respective width. The spiral angle 
approaches very nearly, or is often exactly, the same asin Cerith. ornatissumum. 
There is no marked difference between the posterior keels of the two species. 
But while in C. ornatissimum the anterior keel separates a small distance from the 
suture, when on the last whorls approaching the aperture, the same is in Cerith. fertile 
always strictly sutural, but much stronger than the anterior; and in addition to 
the middle keel there is a fourth one present, and quite distinct in young speci- 
mens, gradually becoming obliterate in older. (Vide Pl. XIX, Fig. 5.) These 
differences are therefore greater than those between the two above-mentioned 
European species. 
It is important also to mention the Transylvanian species, which I have noted 
as Cerith. rotulare in the Jahrb. Geol. Reichs-Anst. Wien, 1863, Vol. XIII, p. 51. 
This species is a much more slender form, and differs from Cerith. Mosense appa- 
rently only by the very considerable thickness of the shell and more concave whorls. 
Casts of Cerith. fertile are quite smooth ; the aperture is quadrangular, wider 
than high, terminating anteriorly in a short, laterally bent canal. 
Locality.—N. of Odium, in yellowish, calcareous sandstone with Am. inflatus, 
dispar, and others. 
Formation.—Ootatoor group. It is interesting to see that this species occurs 
with precisely the same association. of Ammonites as the similar forms to which I 
alluded occur in Europe, while their other associate Gault-species, Cerith. trimonile, 
has as yet been found in India only in the highest beds. 
