PULMONATA. 91 



No. 39. Limn^ea tumida. F. E. Edwards. Tab. XIII, fig. 6 a — b. 



L. testa ovato-acutd, ventricosd, series vel septies circumvolutd ; spird elevatd, apice 

 acuminato ; anfractibus convexis, ultimo tumido : aperturd ovatd, ampld, bessem totius testa 

 in longitudinem fere cequanti ; margine columeUari reflexo ; plied parum tortuosd, eminenti, 

 rotundatd, in medio sub-callosd. 



An ovate, ventricose shell, with an elevated, pointed, rather subulate, spire ; 

 volutions six or seven, the early ones increasing in size slowly, the last two more 

 rapidly; the upper parts forming the sides of the spire are rather flattened, as in 

 L. pyramidalis; the body whorl large and tumid. The aperture is ovate, and in 

 length nearly equal to two thirds of the whole shell ; the anterior margin, where it 

 joins the columella, is slightly reflected ; the columella itself is not much twisted, and 

 the fold is prominent, round, and thickened towards the middle. 



This species may be distinguished from L. gibbosida, by the round columellar fold 

 and longer spire ; and from L. fusiformis, by the more convex volutions, the tumid 

 body whorl, the longer aperture, and the nearly straight fold. 



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



Locality. — Headon Hill. 



No. 40. LimNjEA coltjmellaris. /. Sowerby. Tab. XIII, fig. 9 a— b. 



Limnea columellaeis, Sow. 1826. Min. Con., vol. vi, p. 53, t. 528, fig. 2. 



— — 1 Lyell and Mur. 1829. Sur les depots lacustres, &c, du Cantal. 



L. testa ovato-ventricosd, sub-turritd, quinquies vel sexies circumvolutd ; spird brevi, 

 apice acuto ; aperturd ovali, dilatatd, bessem totius testa in longitudinem fere cequanti; 

 plied columeUari rotundatd, callosd, valde contortd, pro-eminenti. 



I am indebted to Mr. Sowerby for the use of the original specimen described by 

 him of this species. It is a ventricose, oval shell, with a short pointed spire, and 

 formed of five or six very convex whorls, rather depressed at the suture, whence the 

 shell presents a subturreted appearance; the aperture is large, effuse, and nearly as long 

 as two thirds of the whole shell ; the thick, callous-like fold is round, very prominent, 

 and much twisted. 



If it were not for the convexity of the whorls and the size of the aperture, I should 

 be inclined to consider this shell to be only a variety of L. fusiformis; and that the 

 unusual contortion of the fold, a character to which individuals of that species occa- 

 sionally approach very nearly, is accidental. But in this species, the pyramidal shape, 

 which always distinguishes the spire of L. fusiformis, is altogether wanting. From 

 /.. tumida, which it resembles in the size of the aperture, it is also separated by the 



