ADDENDUM. 189 
Scacenra Lata, 8. Wood. Addendum Plate, fig. 29. 
Locality. Cor, Crag, Sutton. 
The above figure represents a shell recently sent to me from the Cor. Crag of Sutton, 
by Mr. Canham, which, I believe, is specifically distinct from any other yet described. It is 
thin, nearly transparent, very inequilateral and tumid, and with a smooth exterior. It slightly 
resembles Sc. elliptica ; but it is more transversely elongate. It is the right valve and is 
quite free from that sinuosity in the dorsal margin which forms the distinguishing 
feature of this valve in e/iptica. My shell is also edentulous in this valve. I have found 
in the Cor. Crag from the same locality a specimen of what appears to be the left or 
opposing valve of the same species, and this has one obtuse cardinal tooth, and is similarly 
inequilateral. ‘The second specimen, which is not quite perfect, has been m my possession 
these thirty years and more, and I have hitherto been unable to refer it ; but the dis- 
covery of the specimen now figured seems to throw light upon it. 
The nearest shells to which this species approaches seem to be the older tertiary 
species Lrycina latens, Desh., and L. emarginata, Desh, ‘ An. sans vert du Bas de Par.,’ 
vol. i, p. 712, Pl. LI, figs. 24—27, and Pl. LIT, figs. 13—15. 
Turacia inruata, J. Sow., var. dissimilis. Addendum Plate, fig. 27. 
Locality. Cor. Crag, near Orford. 
A single specimen as above represented has recently rewarded my researches, and from. 
its peculiar form I think it desirable to have it figured. The species to which, as a 
variety, | have doubtfully referred it is somewhat variable, and I am unwilling, therefore, on 
the strength of a solitary specimen to describe it as a distinct species. ‘The posterior 
slope is rugose, but it has not the regular shagreen character of Zr. pubescens, nor the 
convex or protruding ventral margin or sinuation of convera. Should further specimens 
turn up preserving with integrity the distinguishing characters of this specimen, I should 
propose to assign it as a species under the name of Thracia dissimilrs. 
Venus dysera, Brocchi, is given in Mr. A Bell’s‘ English Crags ’ as a species from the 
Cor. Crag, and Mr. Robert Bell has lately sent to me a small specimen from that Crag 
at Sutton with this name attached. his is, I believe, merely the young state of Venus 
imbricata, and J have several similar specimens in my own cabinet. 
