90 EOCENE MOLLUSCA. 



In the general contour, and in the proportions of the aperture, the present species 

 closely resembles L. convexa ; but the small, flat, sulcated fold separates it from that 

 species. 



Size. — Axis, 1 inch and 3-10ths ; diameter, rather more than 6-10ths of an inch. 

 Localities. — Headon Hill. French .- Pierrelaie. 



Sect. b. Columellar fold rounded or sub-acute. 

 No. 38. LIMN.EA fusiformis. /. Soioerby. Tab. XIII, fig. 8 a — g. 



LymnjEA fusiformis, J. Sow. 1818. Min. Con., vol. ii, p. 155, tab. 169, figs. 2-3. 

 Limnea — G. Sow. Genera of Shells. 



— — Lyell and Murch. 1829. Sur les de'pots lacustres, &c., du Cantal. 



L. testa ovato-acutd, sub-fusiformi, Icevi ; anfractibus septenis vel octonis, sub-planis, 

 ultimo ventricoso: aperturd ovatd, spirant in longitudinent vix cequanti ; columella marginatd ; 

 plied columellari rotundatd aut sub -acuta, parum tortuosd. 



Far. deformis, (fig. 8 c — e,) testa breviori; anfractibus sex vel septem, veniricosioribus .- 

 aperturd rotundato-ovali, spirant in longitudinent superanti ; plied columellari rotundatd, 

 eminentiori. 



A smooth ovate-acute shell, formed of seven or eight whorls, the upper sides of 

 which are nearly straight, giving a regular conical form to the spire, which is elevated 

 and pointed; the last whorl is ventricose ; the lines of growth conspicuous and sharp. 

 The aperture is ovate, moderately large, and nearly as long as the spire ; occasionally 

 the anterior part is somewhat contracted, imparting a sub-fusiform shape to the shell 

 The columellar fold is thick, and, generally, rounded ; but sometimes it presents a 

 rather sharp anterior margin ; it is slightly and gracefully twisted. 



Of this species, as of L. caudata, a variety occurs (fig. 8 c — e) in which the shell 

 is much shorter, the volutions very ventricose, the aperture roundedly ovate, and the 

 fold rounded and prominent. 



The contraction of the anterior part of the aperture, causing the fusiform shape to 

 which Mr. Sowerby refers, frequently occurs, but it is not by any means a constant 

 character ; in fact, the aperture is more generally somewhat effuse, as represented in 

 the figure 8. 



This species approaches L. pyramidalis more nearly than any other of the fossil 

 Limncece ; but the flatness of the sides of the spire, and the rounded fold, are 

 characters by which it may easily be distinguished. The variety resembles the short 

 variety of L. caudata ; but the whorls are more ventricose, and the fold is not com- 

 pressed and sulcated, as in that species. 



Size. — Axis, 2 inches nearly; diameter, 8-10ths of an inch. 



Localities. — Hordwell, Headon Hill, Sconce. French .• Aurillac in the Cantal. 



