86 KOCENE MOLLUSCA. 
Linea LoneiscaTa, Lyell and Murch, 1829. Mém. sur les dépots lacustres tert. du 
Cantal. 
LIMN®A — Bouill. 1836. Cat. des coq. foss., &c., p. 157, No. 6. 
= — Gratel. 1838. Cat. des débris foss., &c., du Bassin de la Gironde, 
p- 33, No. 100. 
LyMNZA — Desh. 1838. Lam. Hist. Nat. &., 2d edit., vol. viii, p. 422, No. 7. 
L. testa levi, elongata, sub-turritd, acuminata: anfractibus sex aut septem, convexius- 
culis ; suturis sub-depressis : apertura ovato-acutd, antice dilatatd, spiram in longitudinem 
vie equanti ; labro parum expanso ; columelld marginatd ; plied columellari lata, compressa, 
parum eninenti, bipartita. 
Var. pistorta; testd longiort, angustiori, anfractibus plus decurrentibus ; apertura 
breviort. 
This Limnzea is more abundant, and, although it presents many varieties of form, is, 
perhaps, better characterised than any other fossil species. It is a smooth, elongated, 
narrow, subturrited shell, composed of seven or eight convex whorls, somewhat 
depressed at the suture. The aperture is oyal, rather effuse in front, and, in the 
typical form, is a little shorter than the spire; the inner lip is thick, but does not 
extend much beyond the aperture. The columellar fold is broad, flat, not very 
prominent, and widely but not deeply sulcated. 
A variety frequently occurs (fig. 3 e—A), in which the line of the suture runs below 
the wide part of the whorl, giving an irregular distorted appearance to the shell, and 
shortening the aperture, the length of which barely equals two fifths of the whole 
shell. 
Although there can be but little doubt that this is the true Lymnée efilée of Brard, 
the columellar fold does not correspond with the description given by M. Deshayes, 
in which it is represented to be small and rounded; but in the few French specimens 
which I have had an opportunity of examining, the columellar fold corresponds with 
that of the English specimens. I presume, therefore, that the form described by 
M. Deshayes was a modification of the more general form. 
The shell figured and described by Brard as L. pyramidalis, appears to me, as 
I have already stated, from its elongated narrow shape, the form of the aperture, 
and the slight elevation of the fold, to be merely an adult specimen of this species— 
similar to that represented by fig. 3c and d. The “double suture,” or “narrow 
spiral riband,” running along the edge of the suture, which Brard mentions as 
distinguishing L. pyramidalis, frequently occurs in this, as well as in other species ; 
it is not, however, a constant character in any, and cannot be relied upon as a specific 
distinction. 
A form occurs, rather plentifully, in Hordwell Cliff, which Mr. Wood (‘ Lond. 
Geol. Journ.’ vol. i, p. 118,) has referred to Z. strigosa, (Brogn.) That species, 
apparently, was proposed from casts or mutilated specimens, and is a questionable 
