86 
pkoceedings op the scientific association. 
amples are smaller than those from Haiti. A specimen 
in the British Museum from the latter place is labelled 
V. circinaria } but it is not Cytherea circinata , nor even 
nearly allied to it. 
When describing Cytherea juncea from Cnmana I omit- 
ted to point out the close kinship between that fossil and 
C. circinata. 
Chama involuta n. sp. PI. II, f. 5. 
Left (attached) valve deep internally, very convex ex- 
ternally, often spiral, completing a turn and a half, cov- 
ered externally with distant large foliaceous scales more 
or less erect, between which are small irregular diverging 
granose ridges. Eight valve patulous, ornamented with 
numerous close concentric sinuous foliaceous laminae. 
TJmbones large, prominent, spiral. Margin and laminar 
cardinal tooth crenate. 
Mr. Yendryes suggested that this might be a Dicer as ; 
but I see no ground for referring it to that genus. It ia 
certainly a very spiral chama ; but otherwise its charac- 
ters are in all respects those of the genus. It is appa- 
rently always attached by the umbo cf the left valve, 
and the place of attachment is generally marked by the 
remains or impressions of the septa of corals. It has some 
resemblance to a recent species found in the Westindies, 
which if I have identified it correctly is Ch. ruder alls Lam. 
but besides other considerable differences the latter is 
always attached by its right valve. 
Plicatula vexillata n. sp. PI. II., f. 7. 
Ineqnivalve, irregularly fanshaped ; valves, usually with 
the disk almost smooth, adorned towards the margin by 7 
or 8 stout obtuse radiating ribs along each of which are 
disposed a few lines of reddish brown (probably red when 
