232 EOCENE MOLLUSCA. 
Localities Highgate, Hornsey, Potters’ Bar, and Clarendon Hill, at which last 
locality both varieties occur. 
The specimens represented by figs. 3a and 3, form part of Mr. Wetherell’s col- 
lection. 
No. 156. PLEUROTOMA PYRULATA, Deshayes. Tab. XXVII, fig. 7 a, 4. 
PLEvROTOMA PyRULATA, Desh. 1824-37. Descr. des coq. foss., &c., vol. ii, p. 449, t. 66, 
figs. 1—3. 
P. testi elongatd, angusta, piruliformi, spiraliter lineatd: spird mediocriter elevata, 
sub-conicd ; anfractibus angulatis, in medio convexiusculis, antice sensim attenuatis ; mar- 
ginibus posticis declivis, vie cavatis, concentrice tenuissime lineatis ; ultimo anfractui in 
canali pre-longo terminanti ; lineis spiralibus acutis, irregularibus, inequalibus, lineis tnere- 
menti fortiter decussatis: apertura elongato-ovali ; labro parum arcuato ; sinu latiusculo, 
profundo, in margine collocato. 
Shell elongated, narrow, concentrically lined: the spire, formed of eight or nine 
volutions, is pointed and moderately elevated, not equalling in length a third part of 
the whole shell; the whorls are convex at the middle, bluntly angulated at the 
shoulders; the posterior margins but slightly depressed, giving a nearly conical form 
to the spire; slightly thickened at the edge, where they present two strong, prominent, 
raised lines, which run round the suture, and form a border to the whorls; the space 
between the suture and the shoulders is slightly channeled, and covered with several 
very slender, unequal, raised lines ; the body-whorl diminishes gradually towards the 
base, and terminates in a very long and nearly straight canal. The gradual tapering 
of the whorls, joined to the rather short, conical spire, gives to the shell somewhat of 
the form of a long, narrow pear, from which appearance the specific name is taken. 
The spiral lines over the middle and front parts of the whorls are numerous, irregular, 
and unequal, slender thread-like lines alternating with thicker and more prominent 
lines; all are beautifully and regularly decussated by the strongly marked lines of 
growth. The aperture is of a long, narrow, oval form; the outer lip slightly expanded 
towards the middle; and the sinus, which is placed in the middle of the margin is deep 
and not very wide. 
The French shells, in their typical form, are narrow, with a rather short spire; 
but, apparently, specimens from different localities present considerable variations, 
not only in the relative height of the spire and width of the shell, but also in the stria- 
tion. The specimens from Compiegne, for instance, as M. Deshayes has recorded, 
have the spire more produced, the angle of the whorls more prominent, and the con- 
