41 



Genus Strophodonta, Hall. 



(Pal. New York, 1852, II., p. 6,3.) 



Strophodonta, sp. ind. 



PI., Figs. 13-1.5. 



Ohs. — Crashed and fragmentary examples of a Stro- 

 phomenoid shell are numerous in the rock from the Silver 

 King Mine, bearing many delicate, curved, radiating costae. 

 The chief point of interest is the presence of a crenulated 

 hinge-line, the impressions of numerous transverse denticles. 

 This character indicates the genus Strophodonta rather 

 than Strophomena. The crenulations extend from one end 

 of the hinge-line to the otlier, on each side the fissure. 

 The shell was semi-oval, and provided with a large 

 number of fine costae, simply radiating on the centre of the 

 valves, but gradually curving outwards on the flanks. 



Loc. — Zeehan, in a greyish-white schistose rock, 



Pelecypoda. 



Genus Leptodomus, M'Coy. 



(Brit. Pal. Foss., 1852, Fascic. 2, p. 277.) 



Leptodomus? nuciformis, sp. nov. 



PL, Fig. 28. 



Obs. — A small shell that it is difficult to refer positively 

 to any genus, but having the general appearance of Lep- 

 todomus, M'Coy. It has an oblong-oval convex valve, 

 with a straight posterior hinge-line, a rather high umbo, 

 a faint indication of a cincture, and numerous well-marked 

 fine concentric rugae that unite towards the ventral margin 

 into groups or bundles representing growth stages. The 

 anterior margin is obliquely rounded, whilst the posterior 

 margin is, although generally rounded, somewhat semi- 

 truncate also. 



Although no absolute proof exists that this is a true 

 Leptodomus, still, from its general resemblance to that 

 genus, I have provisionally placed it therein, with the 

 trivial name nuciformis, from its rounded and compact 

 nut-shaped outline. It is quite sufficiently distinct for 

 future recognition. 



Loc — Zeehan, in the Despatch Limestone, 



