310 CRETACEOUS GASTROPODA 
postice paulo emarginata ; superficie striis spiralibus atque transversalibus decussan- 
tibus notata. 
Spiral angle 118°; sutural angle 3°. 
Height of the last whorl : width of the shell (considered as 1:00) jad) Hats), 
This is easily distinguishable from other known species of the same genus, 
by its very fine spiral and transverse striation and the great width of the last 
volution, as compared with its height. All the whorls are strongly convex and 
posteriorly along the suture somewhat flattened or even sub-canaliculated. 
The strive of growth are strongly bent forward a short distance from the suture, 
and some of them are occasionally coarser than others. The basis of the last 
volution is convex, leaving a wide umbilicus open in the centre. The shell is thin, 
and neither of the margins of the roundish aperture are thickened or callous. 
The species was at first described by Prof. Forbes as Nerita munita. The iden- 
tification of Nat. obliquistriata is somewhat doubtful, though I cannot refer it to 
any other species. 
Locality —N. of Odium, in dark bluish, caleareous sandstone; apparently rare. 
Forbes’ specimens are from a similar sandstone, 
Formation.—Ootatoor group, 
LXX. NERITOPSIS, Grateloup, 1882. 
1. Nerrropsts crassa, Stoliczka, Pl. XXIII, Fig. 7. 
Nerit. testa semiglobosa, crassa ; anfractibus tribus, postice planiusculis, ultimo 
valde inflato atque semi-globoso ; apertura rotundata, postice paulo angustata, mar- 
ginibus interne incrassatis ; labio in excavatione prope marginem anteriorem 
obsolete unidentato ; superficie costulis spiralibus atque transversalibus decussantibus, 
spinulosis ornata. 
Height of shell : width of last whorl (considered as 1:00) ae spo UPZAO, 
Though our specimen is in some respects deficient, it has the aperture per- 
fectly preserved, and thus admits of a certain generic determination. The shell 
itself had a semiglobose shape, the whorls are posteriorly somewhat flattened, 
and the surface is ornamented with spiral and transverse ribbings, which produce 
small, spinose tubercles on the places where they cross each other. The internal 
space of the aperture is round and posteriorly contracted. In the excavation of 
the inner lip there is a small tooth placed nearer to the anterior than to the posterior 
edge. The margins of the aperture are internally strongly thickened, but the 
extreme edge of the outer lip itself is sharp and slightly undulating. With 
reference to the ornamentation, our species bears a strong resemblance to Neritop. 
Robineausiana, VOrb. (Pal. frang. erét., II, pl. 176, figs. 1-4), but is easily distin- 
guished from it by the other characters. 
Locality.—Neighbourhood of Odium, in soft, rather quartzose sandstone. 
Formation.—Ootatoor group. 
