PLEUROTOMARIA. 441 
Description : 
Height (elevated variety) ‘ 5 . 28 mm. 
Basal diameter : : : . 40 mm. 
Spiral angle . : 3. 95e: 
Shell conical-depressed, slightly nnbiligated: ane regular and sharp, the 
angle ranging from 95° to about 110°. Whorls (seven) flat and sloping, with a 
close suture which is scarcely canaliculate. The ornamentation is granulated 
throughout, a feature arising from an elevated decussation of the spiral and radial 
lines. A belt which is studded with a kind of triple tuberculation forms the base 
of each whorl, but the ornaments of this belt are subject to modification, and its 
character is sometimes changed owing to the undercutting of the whorls. 
The sinus-band is anterior, round, and prominent, but not wide. In the earlier 
stages are spiral lines decussated, but in the later stages the growth-lines alone 
are seen, very closely packed (Pl. XL, fig. 1). The body-whorl is relatively large 
with granulate ornament and a blunt belt, or basal carina, richly granulated or 
tuberculated, these tuberculations losing their sharpness towards the anterior 
extremity. Base convex, with spiral ornamentation rather faint, generally 
wanting in the middle portion of the base, though the radial lines are pretty 
strong. Umbilicus rather small, and inclined to be funnel-shaped. Aperture 
subrhomboidal. 
Relations and Distribution.—Originally described from Dundry, Pl. granulata 
swarms in the Sauzei-bed at Oborne and other localities in the Sherborne district. 
There is a wide-angled variety from Milborne Wick (XXXIX, 10) which, toa 
certain extent, prefigures forms that are characteristic of the Parkinsoni-zone, 
e. g. Pl. Palemon. 
382. PLEUROTOMARIA PHYLAX, sp. nov. Plate XU, figs. 4a, 4b, 4c. 
This rather curious shell is found rarely in the Sauzei-bed at Oborne, and may 
be a sport or megalomorph of the more depressed variety of Pl. granulata. The 
sinus-band, however, presents considerable differences. 
Description : 
Height . : E : . 25 mm. 
Basal diameter , : : . 44mm. 
Spiral angle . ee 
Shell conical-depressed, thick. ain: abiliedia. Spire rather convex with 
a very obtuse apex. Whorls (six) sloping regularly to the basal carina, which in 
some cases is rather undercut. The spiral ornamentation is delicate and regular 
