BIVALVIA. 211 



are so intimately connected that no specific character can be pointed out, whereby it 

 can possibly be distinguished or separated from it. 



In the recent shell the umbo appears, in the few specimens I have been able to 

 examine, to be a little more lateral than in the generality of the Crag fossils, although 

 this lateral incurvature of the umbo is quite as distinct in the extreme of its variation 

 as in the living shell. Although considered as extinct by all previous authorities, and 

 to which I submitted when compiling my own Catalogue, the possession of many 

 more varieties, and further examination, have given me reason to dissent from that 

 opinion. The lamellae of the fossil are not often preserved in Cabinet specimens ; 

 when visible they are sharp and erect, and about equidistant, rather less prominent 

 upon the posterior margin, but that is a character upon which two species in the living 

 state have been formed, and is not much to be depended on ; between the lamellae fine 

 radiating striae are visible, corresponding to the crenulated margin of the interior. 



2. Venus fasciata, Dacosta. Tab. XIX, fig. 5 a — c. 



Pectunculus fasciatus. Dacosta. Brit. Conch., p. 188, t. xiii, fig. 3, 1778. 

 Venus Paphia. Pulteney. Hutchins' Hist. Dorset., p. 33. 



— — Mont. Test. Brit., p. 110, 1803. 



— FASCIATA. Bon. Brit. Shells, vol. v, pi. 170, 1803. 



— — Phill. En. Moll. Sic, vol. ii, p. 34, 1844. 



— — Loven. Ind. Moll. Scand., p. 39, 1846. 



_ _ Forb. and Hani Hist. Brit. Moll., vol. i, p. 415, pi. 23, fig. 3, pi. xxvi, 



fig. 7, and pi. L, fig. 7, 1848. 



— Brogniakti. Payr. Cat. Moll. Cors., p. 51, pi. i, figs. 23—25, 1826. 



— — Phil. En. Moll. Sic, vol. i, p. 43, 1836. 

 Chione fasciata. Gray. List Brit. Moll., 1851. 



Clausina fasciata. Brown. Illust. Brit. Conch., pi. xx, fig. 10, 1827. 

 DosiNA — S Wood. Catalogue, 1840. 



Pectunculus fasciatis. List. Hist. Conch., lib. iii, sect. 4, fig. 114, 1688. 

 Encyc. Method,, pi. 276, fig. 2. 



Spec. Char. Testa crassd, compressiusculd, ovato-trigond vel sub-cordatd, inaqui- 

 laterali, latere postico longiore ; lamellatd, lamellis crassis, recurvis, distantibus ; lunuld 

 elongato-cordatd ; umbonibus prominulis. 



Shell thick, somewhat compressed, triangularly ovate, inequilateral, posterior side 

 the longer, and very little pointed ; covered with thick, distant, and slightly recurved 

 lamellae, or concentric ridges ; lunule elongated, heart shape. 



Length, f ths of an inch ; height, f ths ditto. 



Localities. Red Crag, Sutton, Walton-on-the-Naze. 

 Mara. Crag, Bramerton. 



Recent, Mediterranean, Britain, Scandinavia. 



I have only met with true and genuine specimens of this species as far back as the 

 Red Crag, where it was not very abundant. The young state of Venus imbricata, in 

 some of its forms, strongly resembles this shell, except where the lamellae are well pre- 



