12 MOLLUSCA FROM THE CRAG. 



to the axis of the shell, and situate about the middle of the aperture, at the lower 

 part of the body of the shell ; the other upon the columella, midway between the 

 upper fold and the base of the aperture, and is more oblique of the two. The inner 

 lip is thick, especially at the lower part, and reflected, sometimes entirely covering 

 the umbilicus. The specimens are generally quite smooth ; but that I imagine is an 

 accidental circumstance, as vestiges of punctured strise may be occasionally observed 

 within the aperture, or by the removal of the left lip, and the shell was probably, in 

 its recent state, entirely covered with stria? . There is one deep ridge round the 

 upper part of the volution a little below the suture, and an incipient sinus at the 

 upper angle of the aperture. I am strongly induced to think that the inhabitant was 

 an animal more inclined to salt water than to fresh, as the specimens from the Red 

 Crag have attained to a greater size, and appear to have received their full develop- 

 ment as associates with purely marine forms. 



2. Conovulus myosotis (?) Drap. Tab. I, fig. 14, a — b. var. (5, fig. 15. 

 Auricula myosotis. Drap. Hist, des Moll. pi. 3, fig. 16, 17, 1805. 

 Conovulus bidentatus. Gray. 2d edit. Turt. Man. p. 227, pi. 12, fig. 145, 1840. 

 Conovulus myosotis. S. Wood. Catalogue 1842. 



C. Testa oblong o-conicd lavitjata; spird elevatd, apice obtusiusculo ; anfractibus 8, 

 convexiusculis ; columella biplicatd ; labro tenui, simplici. 



Shell elongated, smooth, with an elevated conical spire, and slightly obtuse apex ; 

 whorls moderately convex, with two folds upon thecolumella; outer lip sharp and plain. 



Axis, £q of an inch. 



Localiiy. Red Crag, Sutton. 



Mam. Crag, Bramerton. Recent, Britain. 



Three specimens of this species were found by myself in the Red Crag, associated 

 with deep water, as well as more littoral species, probably carried there by the efflux 

 of the tide upon pieces of decayed wood, its favorite haunt. It has only two folds 

 upon the columella, the upper one is prominent and compressed, placed at nearly 

 right angles to the axis, the lower one is rather more obtuse and oblique. It is larger 

 than any British specimens I have seen, but is less elongated than my recent speci- 

 mens of C. myosotis from France, which have also three folds. Montague says of his 

 Valuta denticulata that it is a variable shell, and that specimens have sometimes as 

 many as four folds upon the columella, while others have only two, and that the outer 

 lip is sometimes denticulated within. 



The same remark is made by Dr. Gould, who considers it probable that no less 

 than six, perhaps seven, shells, figured and described under different names, are only 

 modifications of this one species, arising from age, accident, and locality. 



The Crag shell resembles, in its dentition and ovate form, the recent British species 

 or variety C. bidentatus, Gray, but is much larger, having at least twice its length, with 

 a corresponding diameter. In the figure above referred to the artist has scarcely repre- 



