82 MOLLUSCA FROM THE CRAG. 



depression above and below it. My specimens are smooth and glossy, but they 

 appear as if they had been rubbed, and the greater number of them are rather more 

 slender than the one represented. The costas terminate at the edge of the volution, 

 and the base is smooth. 



7. Chemnitzia filosa. S. Wood. Tab. X, fig. 7, 7 a. 



Turbonilla filosa. S. Wood. Catalogue 1842. 



Ch. Testa turritd, sub data ; anfractibus septem vel octo convexiusculis, longitudinaliter 

 obsolete costatis ; transversim regulariter striatis ; basi rotundato ; aperturd subovatd ; 

 labro extus incrassato, intus laevigato. 



Shell turreted and tapering, with seven or eight slightly convex volutions, longi- 

 tudinally costated ; costas nearly obsolete, transversely striated ; aperture subovate ; 

 outer lip thickened, varicose, smooth within. 



Axis, \ of an inch. 



Locality. Cor. Crag, Sutton. ? Recent, Mediterranean. 



I have found about a dozen specimens of this shell, which appear distinct from 

 any species I am acquainted with. It has about eight thread-like striae equally 

 distributed upon each whorl, which are continued over the obsolete ribs as well as 

 over the base of the shell ; the costas terminate at the edge of the volution, which 

 is somewhat rounded. The outer lip is thickened externally in its adult state, and 

 sometimes the animal has increased the shell beyond its ordinary size, leaving a 

 thickened and obtuse varix upon the exterior. The last volution has from eight to 

 ten erect, obtuse, or varicose costae. The columella is not so straight in this as in 

 most of the species of the genus, which gives the aperture an ovate form, broader at 

 the lower part. 



Some time since Prof. B. Forbes identified this shell with Parthenia varicosa, 

 described in his Report upon the Invertebrata of the iEgean Sea, published in the 

 Report of the British Association, 1843. I should have given that name upon his 

 authority, but, upon referring to the description contained therein, I think there 

 must be some mistake ; that shell is described as having 11 volutions with 18 — 20 

 costae, and as being only half an inch in length. I have, therefore, for the present, 

 left the species with the provisional name of my Catalogue. 



8. Chemnitzia densecostata. Phil. Tab. X, fig. 8, 8 a. 



Chemnitzia densecostata. Phil. En. Moll. Sic. vol. ii, p. 137, t. 24, fig. 9, 1844. 

 Turbonilla cylindrella. S. Wood. Catalogue 1842. 



Ch. Testa aciculatd, subcglindraced ; anfractibus conve.riusculis, costatis; costis nume- 

 rosis, elevatis, inter stitiis striatis ; columella recta subplicatd ; labro sinvpliei, intus lav iaa to. 



Shell suberect, subcylindrical, slender ; whorls slightly convex, costated ; costse 

 numerous, nearly erect, elevated, smooth ; intermediate spaces tranversely striated ; 

 aperture subovate ; columella straight, subplicated ; outer lip simple, not dentated 

 within. 



Axis, \ of an inch. 



