﻿ADDENDUM. 



189 



Scacchia lata, S. Wood. Addendum Plate, fig. 25. 

 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 elliptica. 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 in 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 Erycina latens, Desh., and E. emarginata, Desh, ' An. sans vert du Bas de Par.,' 

 vol. i, p. 712, PL LI, figs. 24—27, and PL LIII, figs. 13—15. 



Thracia inflata, /. 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, I 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 Thr. pudescens, nor the 

 convex or protruding ventral margin or sinuation of convexa. 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 dissimilis. 



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. This is, I believe, merely the young state of Venus 

 imbricata, and I have several similar specimens in my own cabinet. 



