124 



SPECIFIC NAMES OE CYRENA FLUMINALIS. 



water species above enumerated: — Bucciniim undatum, Lit- 

 torina littorea, Nassa reticulata, Purpura lapillus, Tellina 

 solidula, Cardium edule, and fragments of some others. 

 Sevei'al of these I have myself collected entire, though in a 

 state of great decomposition, lying in the white sand called 

 " sable aigre" by the workmen. They are all littoral species 

 now proper to the contiguous coast of France. Their oc- 

 currence in a fossil state associated with fresh-water shells at 

 Menchecourt had been noticed as long ago as 1836 by 



Fig. 17. 



a Interior of left valve, from Gray's Thurrock, Essex. 



b Hinge of same magnified. 



c Interior of right valve of a small specimen, from Shacklewell, London. 



d Outward surface of right valve, from Erith, Kent. 



Dates of Sjiecijic Names, 



Cyrena fluminalis Miiller 1774 



Euphratis Chemnitz 1782 



consol)rina GaiUmid 1823 



trigonula S. Wood 1834 



gemmclarii PhUippt 1836 



Duchastelii Nyst 1838 



Corbicula fluminalis Il'ursch 1853 



MM. Eavin and Baillon, before M. Boucher de Perthes com- 

 menced the researches which have since made the locality 

 so celebrated.* The numbers since collected preclude all 

 idea of their having been brought inland as eatable shells by 

 the fabricators of the flint hatchets found at the bottom 



*D'Archiac, Histoirc des Progrcs, «fec., vol. ii. p. 154. 



