R. Bullen Neicton — Foaaih from Singapore. 491 



?NUCULANA sp. (PI. XXV, Fig. 7.) 



A figure has been drawn of a fragmentary valve which may 

 represent either a Nuciilana or an Anatimi, that is if the shell can be 

 assumed to have possessed a rostration as indicated by the dotted 

 lines. The specimen 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 umbonal 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 lineation is finer than usually obtains in Analiiia, being 

 perhaps more applicable to Nucuhina, although even in that genus 

 the dorsal line appears to be too horizontal, an obliquity being 

 usually apparent descending from the umbo before proceeding in 

 the posterior direction. 



Collector. — Mr. J. B. Scrivenor. 



?NUCUL0ID SHELL. (PL XXV, Fig. 6.) 



The "Nuculoid shell" here referred to is an external view of 

 a narrow, lanceolate right valve, buried in the matrix, and preserved 

 as a natural cast together with the counterpart. The umbo is very 

 anterior, small, and scarcely rising above the hinge-line ; the dorsal 

 and venti'al margins are subparallel ; anterior margin short and 

 rounded ; posterior oblique, produced, and subacuminate ; sculpture 

 consisting of delicate stride of growth, concentrically arranged; no 

 crenulations observable on the hinge area. 



Dimensions. — Length 20, height 8 ram. 



It is not possible to determine more closely the shell which is 

 here figured and briefly described. Probably it is a form related to 

 Nucula, but the absence of crenulations at the hinge area renders 

 such a supposition very doubtful. Further, there is a resemblance 

 in general contour to Conrad's Palaeozoic genus Nuculites, the casts 

 of which in common with the specimen from Singapore bears 

 a narrow notch-like cavity in the anterior region beneath the 

 umbo ; but, again, the want of cardinal crenulations would create 

 a difficulty if included in such a genus. With better material at 

 some future tim« this shell may eventually be identified. 



Collector. — Mr. J. B. Scrivenor. 



?LuoiNA sp. (PI. XXV, Fig. 15.) 

 The specimen referred doubtfully to the genus Lucina is a small, 

 subcircular, rather con)pres8ed, right valve, showing a nearly mesial 

 rounded umbo directed obliquely forward, and having its surface 

 ornamented with numerous, closely-set, microscopical, concentric 

 Btriations, which are more obvious on the ventral and lateral areas 

 than on the umbonal region. In the postero-ventral direction the 

 valve is imperfect ; this has been indicated in the figure by 

 a dotted line. It is impossible to suggest to what shell this 

 fragmentary valve might be related, although interesting for 



