43 
TAB, XIV.—Middle figure 
represents a Cardium, of which I have many specimens, 
found in large masses of hard marle, near Bury St. Ed- 
mund’s, which marle is replete with the Serpule with a 
sharp quadrate shell and round aperture. — It resembles the 
upper one, but the concentric prominent strie are wanting ; 
and approaches nearer to the Plumstedianum, except in the 
breadth of the space covered by longitudinal strie which 
continues further in proportion. 
-CARDIUM nitens. 
TAB. XIV.—Lower right hand figure. 
Spec. Cuar. Roundish, hinge end rather shoul- 
dered; smooth, shining; marked all over 
with faintish longitudinal punctated lines, 
which are rather more distinct at the anterior 
side. 
LT —— 
Generatry from one fourth to one half an inch in 
length as well as breadth ; each shell nearly round, the end 
at which the hinge is situated is rather square, owing toa 
straightness of that end of the shell. Lines of growth indi- 
stinct, sometimes rendered visible by marks of a darker 
colour than the rest of the shells. It is most commonly 
white, but is rather variable, sometimes plain, but generally 
beautifully zoned with a dark bluish tinge. 
This species is found abundantly at Highgate, and oc- 
casionally the specimens are not difficult to detach from the 
dark clay or marle which has envelloped them and presery- 
ed them so perfectly, that they resemble recent shells. 
They are conspicuous for their dark blue-grey concentric 
