PROSOBRANCHIATA. 275 
No. 199. Prevroroma Vorcer:. Phil. Tab. XXX, fig. 13, a, 6. 
Pievroroma Voucert. PAillipi. 1846. (Tert. Foss. Magdeb.) Paleontogr., vol. i, p. 69; 
t. 104, fig. 2. 
— _ Morris. 1854. Cat. Brit. Foss., p. 271. 
P. testd gracilt, fusiform, lurritd, tuberculatd: spird acuminatd: anfractibus convewis, 
ad humeros carinam acutam, serie tuberculorum dentiformium instructam, gerentibus ; 
marginibus posticis latis, concavis, levissimis ; ultimo anfractu pluribus lineis spiralibus 
filiformibus, irregularibus, cincto, antice repente coarctato, in canalem longum producto: 
apertura ovali; labro leviter arcuato ; sinu latissimo, sub-profundo, triangulart, ad carinam 
collocato. : 
Shell slender, fusiform, turreted, tuberculated: spire pointed, elevated, nearly 
as long as the aperture: whorls, six or seven, exclusive of the pullus, convex, sharply 
carinated at the shoulders ; keel prominent, armed with a single row of rather closely 
set, small, tooth-like tubercles; the posterior margins wide, concave, and very 
smooth; the last whorl, which is ornamented over the middle with several thread- 
like, moderately distant, and nearly equal, raised, concentric lines, is contracted 
suddenly towards the front, and produced into a long, straight, and rather wide canal. 
The aperture is oval, the outer lip slightly arched, and the sinus, which is placed 
on the keel, is very wide, moderately deep, and triangular in form. 
In the English specimens, the spire is rather more slender than that of the 
specimen figured and described by Philippi, and the spiral lines on the last whorl are 
nearly equal ; in all other respects the two shells agree perfectly. 
Size.—Axis, 7-12ths of an inch nearly (14 millim.); diameter, rather more than 
2-12ths of an inch (5 millim.) 
Localities.—Potter’s Bar, where this pretty species appears to be very rare. 
Philppi’s specimen is from the neighbourhood of Magdeburg ; but the precise locality 
is not known. 
No. 200. Prevroroma Warterxeynu. Myst. Tab. XXX, fig. 8. 
PLEUROTOMA sTRIATULA. De Kon. (non Dw.) 1837. Coq. foss. de Baesele, &c., p. 27, 
No. 28, t. i, fig. 6. 
= Warerkrynu. Nysté. 1843. Bull. Soc. Géol. de France,vol. xiv, p. 454, No. 29. 
_ — Nyst. 1843. Coq., &., foss. de Belgique, p. 518, t. 41, fig. 4. 
—_ STRIATULA. Bronn. 1848. Index Palzont., p. 1010. ; 
_— Waterkeynit. D'Or, 1852. Prod. de Paleontol, 26° Etage, No. 195, k. 
P. testé elongaté, sub-turritd, undique concentrice lincatd: spird elevatd, acutd : 
