258 CRETACEOUS GASTROPODA 
This species, having an almost smooth shell and a narrow umbilicus, belongs 
to that section of Solariwm, for which Deshayes proposed the name Disculus, 
but there is evidently no reason for such a sectional distinction, and certainly 
not for the introduction of names, equivalent to generic denominations, unless 
we adopt the trinominal system, wherever it appears to be practicable. The 
Sol. Hugianum, Pict. et Roux (Pal. Suisse, 3me. Ser., p. 540, pl. 88, figs. 3-5,) 
differs from our species by its more conical form, anteriorly carinated whorls, an 
apparently much stronger ornamentation on the basis, and a somewhat larger umbi- 
licus. When compared with Sol. Karapaudiense, it is readily distinguished by its 
sharp and angular periphery, while in the former the peripherical keel has the 
appearance of having been turned upwards. The largest specimen of Sol. Vyla- 
paudiense measures 80mm. on the basal diameter, those of Sol. Karapaudiense only 
20mm. 
Localities. —Vylapaudy, Olapaudy, and near Arrialoor, in light coloured or 
yellowish sandstone; rather common. 
Formation.—Arrialoor group. 
LVI. STRAPAROLUS, Montfort, 1810. (Vide p. 253). 
1. SrraParoLus inpicus, Stolizeka, Pl. XX, Fig. 7. 
Strap. testa discoidea, in utroque latere equaliter excavata ; anfractibus nume- 
rosissimis, angustis, levigatis, ultimo supra infraque obtuse angulato, ad peripheriam 
convexo ; striis incrementi minutissimis sed distinctis, extus ad medium anticé valde 
productis, supra atque infra fulcatis ; sectione anfractuum semilunari. 
Width of one whorl, above, : diameter of shell (considered as 1:00) 
m6 9 op : itsheight ... ( 
ie) 0.183 
: Da) mo OSS 
We have only been able to examine a fragment of this species, but the impres- 
sions of nearly all the whorls leave no doubt as to the above mentioned characters. 
The shell is symmetrically planorboid, consisting of remarkably numerous and very 
narrow volutions. The surface is smooth with the exception of the strize of growth, 
which are bent above and below in 8-form, and strongly forward on the back. ‘The 
species evidently approaches in form the eocene Bifrontia anvmonoides, Desh., which, 
as already stated, should most probably be referred to Straparolus. We do not 
know any eretaceous species which we could compare with the Indian fossil, for 
the Discohelix (Cyclogyra) Leana, Gabb, has the whorls much more depressed ; 
and there are no other smooth, cretaceous Straparoli known, which are symme- 
trically concave on both sides. 
Locality.—N. E. of Odium, in a yellowish calcareous sandstone. 
Formation.—Ootatoor group. 
