370 CRETACEOUS GASTROPODA 
LXXXVII. GIBBULA, Risso, 1826. 
1. GippuLa JERDonIANA, Stoliczka, Pl. XXIV, Figs. 6-7. 
Gibb. testa late conica, apice obtusiusculo ; anfractibus quinis sew senis, sub- 
convexis, ad suturam sepe paulo tumescentibus, spiraliter sulcatis: sulcis 6-7, 
equidistantibus ; ultimo anfractu ad peripheriam rotundate-angulato ; basi applanata, 
spiraliter striata, wmbilico moderate-lato ac infundibuliformi instructa; apertura 
subquadrangulari, labio prope recto, labro tenui ad peripheriam valde insinuato. 
Spiral angle 75°- 80°; sutural angle 10°- 12°. 
Height of shell : diameter of its basis (considered as 1:00) we «60°34, 
» of one whorl : its width ( as Ne ea) ... 0°90. 
The broadly conical form and the funnel-shaped umbilicus are very charac- 
teristic distinctions of this shell, of which the nearest allies are several of the 
recent Gibbule from eastern seas. The apex is generally somewhat obtuse, the first 
whorls being a little flattened and in old specimens almost smooth, but on the other 
whorls the spiral sulcations generally are very distinct and crossed by fine oblique 
lines of growth. The posterior margin of the whorls is occasionally somewhat 
thickened. The basis is flattened and spirally striated similarly to the rest of 
the surface of the shell. The outer lip is remarkably deeply insinuated at the 
periphery, not thickened at the margin, the inner lip is, however, almost straight, 
terminating on the umbilical edge with a slightly obtuse point. 
T have much pleasure in naming this species after our distinguished naturalist 
Dr. Jerdon, who has so largely contributed to our knowledge of the Indian 
Vertebrata. 
Locality.—Neighbourhood of Comarapolliam, in whitish sandstone; rather rare. 
Formation.—Arrialoor group. 
2. GIBBULA GRANULOSA, Stoliczka, Pl. XXIV, Figs, 8-9; Pl. XXVIII, Fig. 14. 
Gibb. testa conula, apice sub-acuminato; anfractibus senis seu septenis, con- 
vexiusculis, spiraliter striatis, striis inequalibus, aliernantibus, fortioribus sub-granu- 
latis ; basi swb-convexa, spiraliter dense striata, in medio funiculate-impressa, vix 
umbilicata; apertura sub-quadrangulart ; interne circulari, marginibus interne paulo 
incrassatis, labro ad peripheriam profunde insinuato, labio recto antice applanate 
ac sub-sulcato. 
Spiral angle 70°—72°; sutural angle 6°—8°. 
Height of shell : diameter of its basis (considered as 1:00) on5 — Al0(0), 
» of one whorl : itswidth ... ( ap op) oon OPE 
This species is distinguished by the large number of spiral strize, which 
alternate in thickness, the stronger ones being finely but distinctly granulated. 
The whorls are convex, somewhat constricted posteriorly ; the basis slightly convex 
and densely spirally striated; there is not a very distinct umbilicus present, but 
only a deep, funnel-shaped depression in its place. The inner lip is nearly straight, 
