GASTEROPODA. 177 



rather dilated at the base ; aperture linear, a little expanded below ; vertex truncated, 

 slightly depressed, with an obtuse almost invisible fold upon the base of the columella. 



Axis, I of an inch ; diameter, j^. 



Locality. Cor. Crag, Sutton. Recent, British, Mediterranean, and Arctic Seas. 



This is rather scarce as a Coralline Crag fossil. The longitudinal lines of growth, 

 so distinctly visible on the upper part of the recent shell, are not to be seen in my 

 specimens, which are probably worn smooth. It differs from the young of B. cylindracea 

 in having a distinct spire, in being smooth, transversely, and in its form, which is 

 rather dilated below, like B. jReynlbiensis, but it is more elongated than that shell, and 

 appears to be intermediate between the two. 



7. Bulla Regulbiensis. Adams. Tab. XXI, fig. 4, a — c. 



B0LI.A Regulbiensis. Adams. Micros, p. 640, t. 14, fig. 28, 1798. 

 _ _ Turt. Edit. Linn. vol. iv, p. 351, 1806. 



— OBTUSA. Mont. Test. Brit. p. 223, pi. 7, fig. 3, 1803. 

 _ _ Flem. Brit. An. p. 293, 1828. 



VoLVARiA Regulbiensis. Brown. Ulust. Brit. Conch, pi. 38, fig. 12, 1827. 

 Retusa OBTUSA. - - - - pi. 38, fig. 5-6. 



PLICATA. - - - pi. 38, fig. 1-2. 



— DiscoRs. - - - - pi. 38, fig. 3-4. 

 Bulla minuta. Woodward. Geol. of Norf. t. 3, fig. 1833. 



— OBTUSA. S. TVood. Illust. in Mag. Nat. Hist. pi. 7, fig. 10, 1839. 

 _ — S. Wood. Catalogue 1842. 



B. Testa miymtd, suhci/Undricd ; spird disVmctd, ohtusd, aliquando elevatd ; anfradibus 

 quatuor vel quinque, in mediis coarctatis; suturis profundis ; aperturd ad basim dilatatd; 

 lahro arcuato. 



Shell small, subcylindrical, with a distinct, sometimes slightly elevated, and obtuse 

 spire ; volutions four or five, occasionally contracted in the middle ; suture deep ; outer 

 lip sharp and arched ; aperture dilated below ; inner lip spreading, and without a fold 

 upon the columella. 



Axis, \ of an inch. 



Locality. Mam. Crag, Bramerton. Recent, British Seas. 



This species is, I believe, rare. It is, I presume, an Estuary species, as I have found 

 it recent, out of the reach of salt water, at low tides. Like most of the shells from the 

 Norwich Crag, the few specimens I have seen present considerable variation. Two 

 individuals, sent me by Mr. Wigham for description, resemble the recent shell more 

 than my own specimens, and indeed are rather more slender, while my own are less so. 

 Lines of growth are distinctly visible, and in my recent shell some obscure transverse 

 striae may be seen upon the lower half. Fig. 4 (5 is from Mr. Wigham's specimen. 



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