176 DESCRIPTION OF SHELLS. 
Bulla expansa. (Tab. VII. fig. 18.) 
Spec. Cuar.—Obliquely orbicular, rather square, compressed, striated ; last 
whorl convex near the upper part; spire very short, rounded ; aperture very 
wide, with a short canal above reflected on to the spire; no columella. 
Only two specimens of this shell have been found. It probably belongs to 
the same section as B. lignaria, but with a much more expanded aperture ; near 
the upper part the last whorl is suddenly very convex, which distinguishes it 
from Sigaretus, for which it might be taken. 
Bulla Edwardsu. (Tab. VI. fig. 1.) 
Spec. Cuar.—Oblong-ovate, striated; apex broad, umbilicate; spire con- 
cealed; aperture with the upper two-thirds narrow, the lower broad; strie 
numerous, dotted ; upper edge of the last whorl (the only visible one) narrow, 
rounded ; columella wanting. 
More closely convoluted and approaching to cylindrical than the recent Bulla 
lignaria, from which it also differs in the form of the deeply umbilicated apex, 
whose edge is rounded. Brongniart’s B. Fortisi (Terr. du Vicent. 52. t. 2. f. 1) 
appears to be more elliptical, with the lower part of the aperture less open. 
The species found in the neighbourhood of Paris (B. lignaria, var. Deshayes, 
v. i. 44. tab. 5. fig. 4-6) is hardly distinguishable, except that it is much 
smaller ; the Cutch fossil (Trans. Geol. Soc., 2nd ser. v. 5, pt. 11.328, pl. 26. fig. 1) 
is much more pointed in form, but has the same hollow apex with its rounded 
edge. It is therefore certain that there are several fossil species called by the 
same name; there are also at least two recent ones, as I believe that of the 
Indian seas to be different from the European one. The species found in the 
English Crag appears to be the same as the recent European one. 
Bulla Defranci. 
I believe this to be identical with the shell found in the Paris basin, and 
called B. lignaria by Deshayes. ‘The cylindrical form is characteristic of it. It 
is remarkable that it should also occur at Barton. Mr. Edwards’s Cabinet. 
Bulla evtensa. (Tab. VII. fig. 6.) 
Srec. Cuar.—Short fusiform, striated, umbilicate; apex of the spire sunk ; 
