if. littlfen Nttdon — -Fanil* from Singapore, 491 
? Nco ul/lna sp* (PL XXV, Fig* 7*) 
A figure Lae bean drawn of a fragmentary valve which tnfly 
represent either a Ntiadnnn or an Auatttm, that ia if the shell can be 
spumed to have possessed a rout ration as indicated by the dotted 
linen. The aped men shows an external view of a compressed right 
valve with a short and rounded Anterior Area and a horizontal dorsal 
line which forms the boundary to an obtusely angled, elongate area, 
extending posteriorly from the rather flattened mu I mi ml region. 
The surface of the valve is delicately striated concentrically? and 
slightly wrinkled posteriorly. 
Supposing the specimen originally to have been rostrated, then the 
concentric Initiation is finer I hra.ii usually obtains in Aimtirm, being 
perhaps more applicable to Nueulnnn, although even in that germs 
the dorsal line appears to be too horizontal? an obliquity being 
usually apparent descending from the limbo before proceeding in 
the posterior direction* 
Collector. —Mr* J. B. Sort ve nor* 
TNuouloed aaxtL, (PLXXV.Fig.fi.) 
The *' Nncnloid shell ” here referred to is an external view of 
a narrow, lanceolate right valve, buried in the matrix, and preserved 
as u natural cast together with the counterpart. The umbo is very 
anterior, small, and scarcely rising above the hinge-line ; the dorsal 
und veu I ml margins are subparalUfl; anterior margin short and 
rounded ; posterior oblique, produced, and so haou minute ; sculpture 
consisting of delicate strife of growth, concentrically arranged; no 
erenillations observable on the hinge area. 
Diiiienniott *.—Length 20, height Brum. 
It is not possible to determine more closely the shell which is 
here figured and briefly described. Probably it is a form related to 
Nucuht, but the absence of oren trialions at the hinge area renders 
such a supposition very doubtful. Further, there is a resemblance 
iit general contour to Conrad's Palsuzoio genus Nweidites, the casts 
of which in common with the specimen from Singapore l>ears 
a narrow notch* like cavity in the anterior region beneath the 
umbo ; but, again, the want of cardinal ere mil at ions would create 
a difficulty if mutinied in such a genus* Wuh better material at 
so eu e future time this shell may eventually be identified. 
Coifector.—Mr* J. B, Seri ran or. 
? Loo in a up. (PL XXV? Fig. 15*) 
The specimen referred doubtfully to the genus hnci ua is a small, 
subcircular, milter compressed, riglsL valve, showing a nearly mesial 
rounded uqsho directed obliquely forward? anil having its surface 
ornamented with notiieroiis, closely-set. microscopical, concentric 
atrialI oiiSh which urn more obvious on the ventral htiiI lateral areas 
than ou the umbonal region. In the postero-ventral direction the 
valve is imperfect; this has Ikseu indicated in llm figure by 
a dulled line. It is impossible to suggest to what shell this 
flagmen Utry valve might bo related, ai though inters ling for 
