PULMONATA. 89 



I propose this species with hesitation ; it may be only a variety of L. pyramidalis 

 or of L. gibbosida, but the characters it presents are so mixed, that it is difficult to 

 determine to which species it should be referred. The narrow, flat, and nearly 

 straight fold resembles very closely that of L. gibbosula ; but the spire is more 

 elevated, more pyramidal, the volutions more regularly convex, and the aperture not 

 so effuse. It is distinguished from the typical L. pyramidalis, not only by the 

 columellar fold, which in the latter species is larger, more oblique, and more 

 prominent, but also by the flatness of the sides of the spire, and the greater length of 

 the aperture ; and from the variety of that species, by the more contracted aperture. 

 In the character of the spire, and the contracted aperture, it approaches L. fusiformis; 

 but it is separated from it by the columellar fold, which in that species is rounded, 

 prominent, and more twisted. 



Size. — Axis, 1 inch and 6-10ths; diameter, 8-10ths of an inch. 



Locality. — Headon Hill. 



No. 37. Limn^a ovum? Brogn. Tab. XIV. fig. 12 a— b. 



Limneus ovum, Brogn. 1810. Ann. du Mus., vol. xv, p. 374, tab. 22, fig. 13 a, b. 



— — Brogn. 1811. Journ. de Phys., &c, p. 422. 

 Lymneus — Ferus. 1814. Mem. geol., &c, p. 60, No. 6. 



LymnjEa — Desk. 1824 — 37. Desc. des coq. foss., &c, vol. ii, p. 97, tab. 11, 



figs. 15, 16. 



— — Desk. Encyc. Metb. Vers., vol. ii, p. 361, No. 16. 



— — Bouill. 1836. Cat. des coq. foss. d'Auv., p. 131, No. 13. 



L. testa ovali, sub-ventricosd, acuminata, sub-lavi ; anfractibus sex, convexis, ultimo 

 magno : aperturd mediocri, ad basin sub-dilatatd ; columella marginatd ; plica columellari 

 parvd, compressd, sulcata, antice angulatd, parum tortuosd. 



As I have not had an opportunity of comparing the English with French 

 specimens of this species, the identification cannot be altogether free from doubt. 

 The English shell is nearly smooth, ovate, and sub-ventricose, with a moderately 

 elevated and pointed spire ; volutions six or seven, separated by a conspicuous but 

 not deep suture. The aperture is not wide, but is a little dilated in front, and is about 

 half the length of the entire shell : the columellar fold is small, compressed, obscurely 

 sulcated, very slightly twisted, and scarcely projects into the aperture ; the anterior 

 margin presents an acute ridge, formed by the prolongation of the sharp edge of the 

 peristome ; the inner lip is slightly reflected. 



The aperture is not so contracted in front as M. Deshayes describes that of the 



French shell to be ; it agrees very well with .Brogniart's figure, but not with that given 



by M. Deshayes, although the latter was taken from Brogniart's specimen. In other 



respects the English shells do not appear to differ from the French. 



•12 



