BIVALVIA. 143 



DOUBTFUL. 



4. LuciNA COLUMBELLA, Lamarck. 



LuciNA COLUMBELLA. Lam. Hist, des An. s. Vert., t. v, p. 543, No. 15, 1818. 



— — Basterot. Mem. Geol. des Env. de Bord., p. 86, pi. 5, fig. 11, 1825. 



— — Bromt. Lethsea Geogn., p. 959, t. 37, fig. 15, a — d, 1837. 



— — Dujard. Mem. de la Soc. Geol. de France, torn, ii, pt. 2, p. 258, 



1837. 



— — Dubois de Mont. Foss de Wolhyn., p. 57, pi. 6, figs. 8 — II, 1831. 



— — G. B. Sowerhy. Genera of Shells, No. 27, fig. 6. 



— — Phil. En. Moll. Sic., vol. ii, p. 26, 1844. 



— — Reeve. Conch. Icon. Lucina, pi. 6, fig. 30. 



— vuLNERATA. Be France, sec. Basterot. 



Three specimens of this species are among the Red Crag Fossils in the Wood- 

 wardian Museum at Cambridge ; and as it will be seen by the above references, it 

 was an inhabitant of the Seas which deposited the Bordeaux Beds, found also in the 

 Faluns of Touraine, in the Plateau Wolhyni-Podolien, and according to Philippi, has 

 been obtained at Sortino, in the Val di Noto, it is very possible it may have had 

 an extension into the Red Crag, more especially as a shell resembling this (probably 

 only a variety) is still a living species on the N. W. Coast of Africa. 



No satisfactory information respecting these so called Red Crag specimens could, 

 however, be given by any of the gentlemen connected with the Cambridge Museum, 

 although Professor Sedgwick says he believes them to be true Crag shells, but being 

 myself unable thoroughly to examine their lithological character, and never having 

 seen the same species in any other Collection of Crag Fossils, and in the absence of all 

 knowledge of their correct locality, they must, at least for the present, be considered 

 as not strictly entitled to a place in the undoubted Fauna of that Period. 



DiPLODONTA,* Broivi. 1831. 



Tellina (sp.). Mont., 1803. 



Mysia (sp.). ZeacA, MS., 1819. Brown, 1827. 



Venus (sp.). Broc. Nysf. 



Lucina (sp.). Def. Desk. 



DiPLODONTA. Bronn., 1831. 



Sph.erella? Conrad, 1838. 



Generic Character. Shell somewhat thin, more or less orbicular, equivalve sub- 

 equilateral, externally smooth, or slightly marked by lines of growth, umbones not 

 very prominent. Hinge composed of two cardinal teeth in each valve, the anterior 

 one in the right valve simple, the other bifid, and the reverse in the left, no lateral 



* Etym. AittXo'os, double, ihois, a tooth. 



