122 EOCENE MOLLUSCA. 
Spec. Char. N. testd ovatd, viv elongata, gibbosd, laevigata, subinequilaterali ; pedi- 
regione rotundata ; siphoni-regione oblique truncatd vel obtuse rostratd ; umbonibus depressis ; 
marginibus crenulatis. 
“ Shell suborbicular, transverse, gibbose, smooth; extremities pointed; beaks nearly 
central, margin obtuse, edge toothed.” — J. Sowerby. 
Length, % a inch. 
Locality. ampstead Heath (Wetherell) ; Highgate, Sheppy ? (Hdwards). 
“The radiating structure of this Nucula, common to the species of the genus, is very 
conspicuous, but the inner surface is not striated, as in V. Bowerbankui.”—J. Sowerby. 
The specimens of this species that I have seen are not numerous, and, unfortunately, 
they are not in perfect condition ; the umbones are excessively eroded, thereby reducing 
their natural proportions, giving a slightly rounded outline to the shell. 
Since the type for the preceding descriptions has been set up, several specimens 
belonging to this genus have come under my inspection, which I cannot assign to any of 
the foregoing species ; and although they do not present characters sufficiently determinable 
for specific isolation and description, they are, I conceive, fully deserving of representation 
and notice, and I propose here to give to them provisional names only until they can 
hereafter, by the possession of more specimens, be satisfactorily characterised. 
‘lab. XX, fig. 10, represents the interior cast of a shell from Clewer Green, near 
Basingstoke, kindly lent to me by Mr. Prestwich, and to which I will give the name of 
V. venusta ; it appears to have possessed a smooth margin to the edge of the valves, and 
it has a very slight basal projection on the siphonal side; there is a prominence in the 
anal region, and in its contour it is intermediate between iV. disulcata and NV. prelonga, 
but to neither of those smooth-margined species can it, I think, be referred. The age of 
the deposit in which it is found being greater than that of the two other species strengthens 
the supposition that this is distinct. 
‘Tab. XX, fig. 7, is the representation of a specimen, also from Mr. Prestwich’s cabinet, 
to which the locality Cuffells is attached; this appears to be different from any of the 
foregoing, but it is imbedded in the matrix, and 1 am unable to describe its true characters. 
I give it the name of JV. consobrina ; in outline it somewhat resembles JV. consors, from 
Highgate, but is, | think, too long and too much truncated for that species ; it has a very 
slight elevation in the anal region, but there is no perceptible lunule, although there is a 
slight depression on the dorsal surface extending from the umbo to the verge of the pedal 
extremity ; the shell is thick, nacreous within, and the denticles are large, twenty-four on 
the pedal side, and seven or eight on the other. 
Tab. XX, fig. 6, represents a specimen very recently obtained from the Woolwich 
series at Bickley, by Chas. A. Meyer, Esq.; this shell has been kindly submitted to my 
examination. It is probably distinct, and I will call it for the present JV. gracilenta ; its 
nearest relative appears to be WV. fragilis, but on a comparison with specimens of that 
