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; \ of an inch ; diameter ', yq. 



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. Beyulbiensis, 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. 



Bulla 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. Illust. Brit. Conch, pi. 38, fig. 12, 1827. 

 Retusa obtusa. .... p]. 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. Wood. Illust. in Mag. Nat. Hist. pi. 7, fig. 10, 1839. 

 _ „ S. Wood. Catalogue 1842. 



B. Testa minuta, subcylindricd ; spird distinctd, obtusa, aliquando elevatd ; anfractibus 

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

 labro 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 

 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 strioe may be seen upon the lower half. Fig. 4 b is from 

 Mr. Wigham's specimen. 



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