36 SUPPLEMENT TO THE CRAG MOLLUSCA. 
PLEvROTOMA BipuNcruLA, S. Wood. Crag Moll., vol. i, p. 54, Tab. VI, fig. 3 6 (as P. 
semicolon). 
This shell, which I also doubtfully referred as var. 6 of P/. semicolon, J. Sow, is, I am 
now satisfied, distinct from that species. It differs from the preceding P/. Icenorum in 
several points, viz. in its ornament, in its more fusiform shape, and in the position of the 
sinus of the outer lip, which in this is more central, as indicated by the knobs left on the 
volution. It somewhat resembles P/. dicatena, Grat., but ‘I believe it is different, and it 
differs from the Eocene PU. denticula. 
My. Bell, in the ‘ Ann. and Mag. Nat. Hist. 1871, gives the name of Pleur. pannum to 
my shell. It possibly may be so, but I have not been able to see a specimen of that 
Bordeaux species. The description given by Basterot is insufficient, so that I could not 
venture to refer my shell in reliance on that, and the figure of this species by 
Bellardi, ‘Piedm. Foss.,’ Tab. II, fig. 2, is so inadequate, that it does not represent the 
position of the sinus, neither does his description (p. 27) supply the deficiency. I have 
therefore given to it a new name. 
PLEUROTOMA LINEARIS. Crag Moll., vol. i, p. 56, Tab. VII, fig. 2. 
Localities. Cor. Crag, Sutton. Red Crag, Sutton and Butley. Chillesford Bed, 
Aldeby (Crowfoot and Dowson). Middle Glacial, Billockby. 
‘he red crag form of this shell figured in the ‘Crag Mollusca’ as the recent /zearis, 
possesses the same number of ribs and the same sculpture as on the recent shell, but a speci- 
men from the Middle Glacial sand of Billockby, in a state of preservation unusually perfect for 
that formation, departs from the recent form in respect that it possesses fourteen ribs on the 
body whorl and twelve on the next, or two beyond the respective numbers on these 
whorls possessed by recent shells. I have not, however, thought it necessary to figure 
the Middle Glacial shell, or to assign it as a new species, which, however, it may 
possibly be, as it approaches perpulchra in the character of its ribs and of its 
striation, though not identical with that species. 
PLEUROTOMA ELEGANTULA, A. Bell. Supplement, Tab. III, fig. 8. 
PLEUROTOMA ELEGANTULA, d. Bell. Ann. and Mag. Nat. Hist., p. 8, May, 1871. 
Spec. Char. Pl. “ Shell stoutly fusiform ; whorls T—9 convex, ornamented with close- 
set ribs 10—12 on the second whorl (penultimate ?) ; suture deep ; mouth and canal open ; 
pillar lip reflected ; notch sinuated rather deeply.”—A. Bell. 
