114 MOLLUSCA FROM THE CRAG. 



these have been examined carefully, and their correct specific establishment is not at 

 present upon a firm and stable basis ; and my own species are not given with any 

 great confidence, but more to call the attention of Collectors to their probable 

 existence. 



Specimens apparently belonging to this genus have also been obtained at Barton 

 from the London Clay or Older Tertiaries. 



1. Lepton squamosum, Montague. Tab. XI, fig. 8. 



Solen squamosus. Mont. Test. Brit., p. 565, 1803. 



— — Mat. and Rack. Linn. Trans., vol. viii, p. 48, 1807. 

 _ _ Turt. Conch. Diet, p. 164, 1819. 



— — Dillw. Desc. Cat. Rec. Shells, p. 70, 1817. 

 _ — W. Wood. Ind. Test. p. 16, 1825. 



Psammobia punctuea. Brown. Illust. Conch. Gr. Brit., pi. 16, fig. 7, 1827. 

 Lepton squamosum. Turt. Brit. Biv., p. 62, pi. 6, figs. 1 — 3, 1822. 



_ _ Flem. Brit. An. p. 429, 1828. 



_ _ 8: Wood. Catalogue, 1840. 



_ _ Thorpe. Brit. Mar. Conch., p. 49, 1844. 



_ _ G. Sowerby. Conch. Man., fig. 62, 1843. 



_ _ Forb. and Hani. Hist. Brit. Moll., vol. ii, p. 98, pi. 36, figs. 8, 9, 



and pi. 0, fig. 6, 1849. 

 Lutraria squamosa. Gray. Ann. of Philos., 1825. 



— — Hartley. Recent Shells, vol. i, p. 28, Supp., pi. 9, fig. 47. 



Lepton squameux. Chenu. Traite Elem., p. 47, fig. 148. 



. 



Spec. Char. Testa ovato-trigonuld, aquilaterali, compressd, tenui ; utroque latere 

 rotundatd, margine ventrali leviter arcuatd; eleganter ornatd; dente cardinali unico, dentibus 

 lateralibus magnis. 



Shell small, triangularly ovate, equilateral, thin, compressed ; rounded on both 

 sides, ventral margin slightly arched ; elegantly ornamented externally ; hinge with 

 one small central tooth and two large lateral teeth. 



Length, \ of an inch. 



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



One specimen only of this species was found by myself in the sandy portion of 

 the Coralline Crag, at Sutton. The interior is sufficiently perfect for comparison, but 

 the markings upon the exterior are rubbed and obliterated, and although there is 

 some slight difference in the outline of our shell, there is every reason to believe it 

 belongs to the same species as that now living in the British Seas, and to which I have 

 assigned it. The hinge area is large, furnished with a small central tooth, and a 

 double set, as it were, of lateral teeth, the innermost of which are large, diverging at 

 an angle of about 90°, those placed outwardly are small and close to the dorsal 

 margin, between these are deep depressions for the reception of the lateral teeth of 

 the opposite valve. The dorsal margin is short, not extending beyond the lateral 



