88 GASTEROPODA OF THE INFERIOR OOLITE. 
Length of body whorl to entire shell ‘ 262 = 100; 
Spiral angle : : ; #63" 
Shell ovate-oblong, apex acute; spire about fourth tenths of the entire shell. 
Whorls five to six, angular, but the posterior area slopes outwards ; flanks scarcely 
tumid. There are about sixteen rather thin longitudinal costz, which in the 
whorls of the spire are continuous, and form nodes at each of the keels; they 
also form nodes in the keel of the body-whorl, but die out anteriorly. The 
costz decussate with spirals which are wide apart, wavy in outline, and about 
half the thickness of the longitudinals. This produces a regular network, of which 
the mesh is largest spirally. Spiral ornamentation of a fine character is also trace- 
able on the posterior area. 
Aperture very similar to that of P. elaborata, but with rather shorter columella. 
Very slight trace of the umbilical slit. 
Relations and Distribution.—This pretty species has some resemblance to Purpu- 
rina ornatissima, Moore (op. cit.), from the Marlstone of Ilminster. But in Moore’s 
species the shell is more ovate, the whorls are subtumid and very slightly tabulate. 
The ornamentation of Moore’s species more resembles that of P. elaborata. 
P. cancellata is described from a unique specimen in a very good state of 
preservation. It is stated to come from Stoford, and has much the appearance of 
a fossil from the Sowerbyi-bed. 
4. Purporina BeLLona, D’Orbigny, 1850. Plate I, figs. 5 a,b; 5¢,d; 5e, f. 
1850. Purpurtna BELLONA, D’Orbigny. Prod. 1, p. 270. 
1852. _ — — T. J., 2, pl. 331, figs. 1—3. 
1886. Non — —- — Vacek, Fauna von Cap. 8. Vigilio, p. 109, 
pl. 18, fig. 7. 
Bibliography, §c.—This is the regulation name for most Purpurinas from the 
Inferior Oolite. I have already pointed out that D’Orbigny’s type must have come 
from the ‘ Oolithe ferrugineuse,” and is therefore a fossil of the Upper Division. 
The species is capable of numerous subdivisions, some of which might almost be 
raised to the rank of species. 
Description : 
Length of a medium specimen . : . 2iimm: 
Ratio of width to length 5 5 . 662400: 
Length of body-whorl to entire shell : 2. 00.2100; 
Spiral angle : : 60°. 
Shell ovate-oblong, turrited, apex acute. Spire nearly half the length of the 
