158 GASTEROPODA OF THE INFERIOR OOLITE. 
The body-whorl is relatively small, base rather flat. Aperture subquadrate, 
with a straight columella. Canal apparently short, other indications wanting. 
Relations and Distribution—This form appears to have relationship to the 
several species described by Deslongchamps from the Inferior Oolite of Normandy, 
as Cerithium triseriatum, quadriseriatum, &c. With these, unfortunately, I am 
unacquainted. It is noticeable, however, that in this species we lose the compara- 
tively strong longitudinal ornamentation of the vetustwm-group. 
Single specimen from the Inferior Oolite (? Murchisonx-zone) of Coker. 
The Limeforme-Group. 
This group is intended to include Cerithia which are usually rather small, 
often pupoid, and with fine ornaments, where the spiral lines are more 
conspicuous than the longitudinals. The aperture has rather a tendency to 
be subquadrate, columella short, with a short but well-developed anterior canal, 
shghtly reflexed. Judged by the character of the aperture these little shells are 
perhaps more nearly allied to the existing genus Cerithiwm (including Bittiwm) 
than the group last described. In the Lower Oolites of this country Cerithium 
Beanu, and C. limeforme are the two species round which the less common forms 
may be grouped. But these also vary so obviously that it is almost impossible to 
draw a very distinct line. In order to realise how hopeless it is to make “ hard- 
and-fast species” out of this group, let anyone study a well-stocked collection of 
small Cerithia from the Lincolnshire Limestone. And yet it is equally impossible 
to avoid the temptation of making a certain amount of nominal differentiation. 
79. Curitatum Lroxensyi, Hudleston, 1884. Plate IX, fig. 4. 
1884. Crrirutum Lecxensyt, Hudl. Geol. Mag., dec. iii, vol. i, p. 61, pl. iii, 
fig. 12. 
Description : 
Length (restored) ‘ : ; pli gaman 
Width : ‘ : . 4mm. 
Height of whorl to maak : Sto. 
Spiral angle : pen are 
Shell elongate, subturrited ; whorls ) thirteen, flat, short in comparison with 
their width; sutures close. The ornaments consist of finely granulated or 
tuberculated spirals, of which the first is strongest and the fifth the faintest. 
The longitudinals are irregular as in C. Beanii, frequently not reaching to the 
