94 MOLLUSCA FROM THE CRAG. 



appear ever to have the least vestige of striae, and the peristome is much reflected and 

 turned over, so as to form an obtuse varix, producing a nearly continuous rib up the spire. 



9. SCALARIA CLATHRATULA. Turt. Tab. VIII, fig. 19, a b. 



TURBO CLATHRATULUS. Turt. Linn. vol. iv, p. 500, 1806. 



Turt. Conchological Dictionary, p. 208, 1819. 



TURBO PARVUS. Maton and Racket. Trans. Lin. Soc. vol. viii, p. 171, pi. 5, fig. 1, 1807. 

 SCALARIA MINUTA. J. Sow. Min. Conch, t. 390, fig. 3-4, 1825. 



PSEUDO-SCALARIS. Dubois deMontp. Foss. deWolhyn. Pod. p. 43, pi. 1 1, fig. 36-37, 1831 . 



PULCHELLA (?). Phil. En. Moll. Sic. vol. i, t. 10, fig. 1, 1836. 



CLATHRATULA. S. Wood. Catalogue 1842. 



Sc. Testa turritd, Icevigatd, imperforatd; anfractibus convexis, contiguis, costettatis ; 

 costellis confertissimis, lamettiformibus ; aperturd subcirculari ; marginibus acutis. 



Shell turreted, smooth, and imperforate, with nine convex, contiguous volutions ; 

 costellae rather variable in number, generally numerous, lamelliform, thin, depressed, 

 and reflected; aperture subcircular, with a thin, reflected, sharp, and elevated margin. 



Axis, | of an inch. 



Locality. Cor. Crag, Sutton. Recent, British Seas. 



This species is exceedingly abundant and variable in the number of costae ; in 

 some there are upwards of 20, while others have not more than 14 on one volution. 

 It appears to differ from the 8. Trevelyana principally in its more elongated form and 

 less reflected costae. I have not yet seen this species from the Red Crag, although a 

 strong shell, and very abundant in the older formation ; in a recent state it is a very 

 rare shell, and may probably be one of the species now dying out. 



10. SCALARIA TREVELYANA. Leach, MS. Tab. VIII, fig. 20. 



SCALARIA TREVELYANA. Winch. Geology of Lindisfarn, An. of Philosophy, xx, p. 434. 

 TREVELIANA. Thorpe. British Marine Conchology, p. 254, fig. 27, 1844. 



Sc. Testa turritd, elongato-conicd, latiusculd, imperforatd, Icevigatd ; anfractibus con- 

 vexis, subdisjunctis costettatis ; costis tenuibus, rejlexis, crebris, depressis. 



Shell turreted, elongato-conical, imperforate, smooth; whorls convex, slightly 

 detached ; with numerous depressed costae, thin and slightly reflected, about sixteen 

 on the last volution ; aperture suborbicular. 



Axis, f of an inch. 



Locality. Red Crag, Sutton. Recent, British Seas. 



I have found but one specimen of this shell, which appears to agree so well with a 

 recent individual of S. Trevelyana in my possession, that I am induced to give a 

 figure of it, although it is not perfect. The last six species have the convoluted tube 

 quite smooth, and free from lines or striae of any kind. Their specific separation 

 depending principally upon the form and number of the reflections of the peristome, 

 which generally produce a continuous line of rib along the spire, in a slightly oblique 

 direction. A larger number of specimens than I possess may possibly remove some 

 of these distinctions. 



