FOSSIL SHELLS OF THE CRAG. 463 



A shell figured by Brown, in his Illustrations of British 

 Conchology, called Diaphana Candida, pi. 38, fig. 13, 14, 

 somewhat resembles this in outline, but the spire is visible ; 

 and as there is no accompanying description, little can be said 

 respecting it. The inner lip is slightly folded back, forming 

 behind it a small umbilicus, and the outer one expanding 

 towards the base, forms a compression round the upper part 

 of the whorl, a character not unusual in many species of this 

 genus. The aperture diverges from the upper part, assuming 

 a suboval shape. Externally striated, and the outer lip thick- 

 ened, behind which is seen the muscular impression. 



Bulla conulus, Desh. Fig. 6. 



Bulla conulus, Deshayes, Coq. Foss. des Env. de Par. ; pi. 5, fig. 34, 36. 



Shell ovato-conical, striated, columella subuniplicated, aperture linear, base 

 dilated, spire hidden. Length \, diameter £ of an inch. 



Coralline Crag, Sutton. 



This is one of the few eocene shells found in this deposit. 

 I presume it to be identical, according to Deshayes' figure 

 and description, except that he says " basi tenuissime stria- 

 ta," whereas the crag shell (when not eroded) is striated all 

 over. There is a shell figured by Brown, called Volvaria 

 pellucida, which may perhaps be the same, but according to 

 the figure the upper part is too much truncated. 



Bulla concinna, Nob. Fig. 7. 



Shell subcylindrical, spirally striated, apex concealed, aperture linear, 

 slightly gaping at the base, inner lip at the lower part folded over an 

 umbilicus. Length § of an inch, diameter f of its length. 



Coralline Crag, Sutton. 

 All my specimens have the outer lip broken, but the shell 

 is very distinct in many points. It is shorter and more gib- 

 bous than Bulla cylindracea, with the aperture wider. The 

 distinct lines of growth cut the deep-seated striae at right 

 angles, giving the shell a pretty cancellated appearance ; the 

 rounded volutions of the upper part of the shell produce a 

 funnel-shaped umbilicus in the place of the spire, and the 

 fold of the inner lip forms a distinct umbilicus at the base. — 

 Twenty specimens of the shell present not the least variation. 



Bulla cylindracea. Fig. 8. 



Bulla cylindracea, Montague, Test. Brit. tab. 7, fig. 2. 

 „ convoluta, Min. Con. tab. 464. 



Shell cylindrical, spirally striated, aperture linear, narrow, vertex imibili- 

 eatcd. Length I an inch. 



