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 hving 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. S. IFood. Tab. XXI, fig. 10, a — c. 



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

 BuLL-«A SCULPTA. <S. JFood. Catalogue 1842. 



£. Testa j)usilld, ovatd, termi,fra(/ili ; anfractibus superne coardatis, densissime striatis ; 

 striis divergentibus, sculptis, cateniformibus ; sjnrd depressd, vice distindd ; aperttird 

 patente, labia acuta prominente, umbilico 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, \ ; 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 suSicient difference in the specimens I possess to justify their being considered 

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

 Mag. Nat. Hist. 1834, p. 353, to differ from 5. catena in having distinctly-impressed 

 dots upon its surface, instead of oval, raised, chain- like striae, 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. 



