PROSOBRANCHIATA. 313 
form in the animal, and is not due, as in P. furbida, to the successive terminations 
of the sinus, which in the French shells is placed in the margin of the whorl, and not 
on the shoulder, as in this species. These two shells, therefore, cannot, with pro- 
priety, be referred to the same species ; and D’Orbigny has in fact distinguished the 
French shells by the specific name pseudo-colon. 
The shells from’ Basele, Boom, Schelle, and Antwerp, referred in the first 
instance by Nyst, and afterwards by De Koninck, to P. co/on, are also specifically 
distinct, and have been subsequently separated by Nyst, under the name of P. crenata. 
There still remain to be noticed certain shells from Vliermael and Lethen ; these, 
in the first instance, were also referred by Nyst to P. colon; but that author, in his 
description of the fossils of Belgium, has erroneously considered P. colon of Sowerby 
as specifically distinct from P. ¢urbida of Solander, and has treated the shells in 
question as belonging to P. turéida. I have not seen any specimens of the Vliermael 
and Lethen shells ; but, judging from the specimen figured in Nyst’s work, apparently 
a full-grown shell, I do not consider that it has been correctly referred to the present 
species; the spire is shorter and more conical, the whorls are more convex, the 
posterior margins wider and less depressed, and the sutural edges not thickened ‘nor 
girt by the prominent, raised lines found in the present species; the tubercles on 
the shoulder are much less prominent, the body whorl is contracted in front into 
a narrow, somewhat lengthened, canal, the outer lip is not so much curved, and 
the sinus is apparently triangular and much wider and shallower. 
Size.—Axis, 1 inch and 1]-12ths; diameter, rather more than 7-12ths of an inch. 
Localities.—Barton and Highcliff, at both of which places it is very common. In 
Morris’s catalogue, Highgate is also given as a locality for P. colon; but I am not 
aware of the present species having been found there. 
No. 238. Pxievroroma tiegata. F. #. Edwards. Tab. XXXII, fig. 12 a, 0. 
P. testa scabra, elongato-turbinatd, sub-fusiformi, concentrice fasciolis crassis, quasi 
Juniculis, ligatd : anfractibus convexiusculis, ad humeros curvi-crenatis ; marginibus posticis 
latis, transversim tenuiter lineatis, et sulco profundo exaratis, ad suturam incrassatis, longi- 
tudinaliter crasse plicatis ; ultimo anfractu conpideo, in canalem latum, brevem, ad basin 
paululo emarginatum, producto ; fasciolis concentricis crassis, preeminentibus, sub-distan- 
tibus, rotundatis, interstitiis sub-planis : aperturd oblongo-ovali ; labro valde arcuato, acuto : 
sinu latiusculo, profundo, marginibus parallelis, ad humerum collocato ; columella contortd 
sub-callosd, antice cristata. 
Shell rugged, elongated, fusiform, and ornamented with thick, rounded bands, as if 
bound with cords ; the spire, formed of eight or nine volutions, is nearly conical, and 
moderately elevated, being as long as the aperture. The whorls present round the 
40 
