180 MOLLUSCA FROM THE CRAG. 



such as to permit of correct description, but it does not appear to correspond with the 

 "fasciis binis incrassatis' of M. Loven. Mr. Alder informs me that this species has 

 been found in a living state upon the coast of Northumberland. A slight contraction 

 in the upper part of the volution takes from the otherwise nearly quadrate contour of 

 the shell. 



2. BuLL^A scuLPTA. 8. Wood. Tab. XXI, fig. 10, a — c. 



Bulla catenata. S. Wood. lUust. in Mag. Nat. Hist. p. 460, pi. 7, fig. 2, 1839. 

 BuLL^A SCULPTA. S. Wood. Catalogue 1842. 



B. Testa pusiUd,ovatd, te)mi,fragili; anfractihus superne coardatis, densissime striatis ; 

 striis divergentibus, sciilptis, eaten if ormibus ; spird depressd, viw distinctd ; aperturd 

 patente, labio acuta prominente, mnbilico parvo. 



Shell small, ovate, thin, and fragile ; volutions slightly contracted round the upper 

 part ; spire depressed, scarcely visible ; covered externally with diverging chain-like 

 striae ; outer lip curved ; inner lip sharp and prominent, with a small umbilicus ; mus- 

 cular impression slightly visible. 



Axis, I ; diameter, \ of an inch. 



Locality. Cor. Crag, Sutton. 



Only two or three specimens of this elegant shell have as yet come into my pos- 

 session, and these appear somewhat to resemble B. catena, Montague ; but a specimen 

 of the latter, obligingly sent to me by Mr. Alder, differs in the following characters : 

 — it has a wider aperture, is less convolute, more quadrate, or more expanded, in the 

 lower part of the outer lip, and wants the inflected and prominent portion of the inner 

 lip ; a large series of both species might, perhaps, show a greater resemblance, but 

 there is sufficient difference in the specimens I possess to justify their being considered 

 as distinct. Bulla pmictata, Adams, Lin. Trans, v. t. l,f. G — 8, is stated by Dr. Turton, 

 Mag. Nat. Hist. 1834, p. 353, to differ from i?. catena in having distinctly-impressed 

 dots upon its surface, instead of oval, raised, chain- like strias, which form the lines in 

 B. catena, and the animal is said to be destitute of a gizzard. Our shell is covered 

 with regular chain-like striae, similar to those upon B. catena, and was, no doubt, 

 white and semitransparent in its recent state. 



