84 EOCENE MOLLUSCA. 



subidatd : aperturd magna, in medio dilatatd, antice coarctatd, spiram in longitudinem 

 superanti : plied columellari compressd, proeminenti, valde obliquatd, obscure sulcata. 



Var. abbreviata; testa anfractibus septem vel octo ■; spird breviori ; aperturd longiori. 



Shell ovate-acute, ventricose, smooth, composed of eight or nine convex volutions, 

 of which the first five or six increase slowly, and the last enlarge rapidly ; so that the 

 spire assumes a conical awl-like shape, while the body-whorl is very ventricose. The 

 last two volutions frequently present concentric, obscure, irregular corrugations, giving 

 a crumpled appearance to the shell, similar to that which distinguishes the recent 

 L. stagnalis. The aperture is large, effuse towards the middle, but contracted at the 

 anterior part, and somewhat larger than the spire. The columellar fold is flat, 

 prominent, rather strongly twisted, and generally obscurely sulcated. 



A variety occurs (fig. 2 c) in which the shell is more ventricose, the whorls fewer, 

 the spire shorter, and the aperture proportionally larger, equalling two thirds of the 

 whole shell. 



The L. caudata, in its general appearance and awl-like spire, much resembles 

 L. stagnalis ; but, in the latter species, the whorls are more convex, the body- whorl 

 more ventricose, the posterior part of the aperture more effuse, and the columellar 

 fold is rounded, smaller, and more oblique. Individuals occasionally occur which, 

 from the small degree of convexity in the whorls would, at the first glance, be referred 

 to L. fusiformis ; but they may be easily separated by the columellar fold, which, in 

 the latter species, is rounded, and presents a more graceful spiral than that of 

 L. caudata. 



Size. — Axis 2 \ inch, nearly ; diameter 1 inch. 



Localities. — Hordwell Cliff and Headon Hill. 



No. 31. Limn^ea pyramidalis. Desk. Tab. XIII, figs. 2a — b, and 3a — b. 



Lymn^ea pyramidalis. Desk. 1824 — 37. Desc. des coq. foss., &c, vol. ii, p. 95, t. 20, 



figs. 14, 15. 

 Limnea „ J. Sow. 1825. Min. Con., vol. vi, p. 54, t. 528, fig. 3. 



LimNjEa „ Bouill. 1836. Catal., des coq. foss. de l'Auvergne, p. 124. 



Lymnee pyramidale? Brard. 1810. Ann. du Mus., vol. xv, p. 407, t. 24, fig. 2. 

 Lymneus pyramidalis? Fer. 1814. Mem. geol., &c., p. 60, No. 3. 



L. testa ovato-acutd, ventricosd, lavi ; anfractibus septem vel octo convexis : aperturd 

 magna, antice dilatatd, spiram in longitudinem superanti ; labio parum expanso ; columella 

 marginatd ; plica columellari magna, compressd, obliqud, in medio sub-biparlitd. 



A smooth, ovate-acute, ventricose shell, composed of seven or eight convex whorls, 

 separated by a simple, well-defined, but not deep suture : the aperture, which is fully 

 as long as the spire, is large and effuse ; the inner lip but slightly spread over the 

 body-whorl, and the columella presents a margin formed by the thickened inner lip, 

 and bears a prominent oblique fold, obscurely sulcated. 



