New or Little-known Victorian Fossils. 69 



Measurements. 



Length of shell -.--.. 6.5 mm. 



Width 10 „ 



Greatest height from surface of attachment - 1.5 ,, 



Affinities. — Although the general characters of our specimen 

 come well within the genus, there are no closely related forms 

 among the few species of Craniella yet described. 



Probably the nearest allied form is the variable species from the 

 Hamilton group of New York State, namely C. hamiltoniae, 

 J. HalP. Our specimen, however, is much broader, with a 

 longer posterior border, and having concentric leather than 

 strongly sigmoidal sinuses. 



Observations. — This genus has hitherto been recorded only from 

 Ordovician (doubtfully) and Devonian strata in North America 

 and Europe, and thus its occurrence for the first time in Aus- 

 tralia is further interesting from the fact that it apparently fills 

 in the gap in its geological range, if the Ordovician occurrence 

 can be proved. 



Occurrence. — Our example of the above species was found 

 attached to the external surface of a species of Cycloceras, from 

 the tine blue-grey argillaceous rock near the Botanical Gardens, 

 South Yarra, Melbourne. It was found during the work on the 

 Yarra Improvements. Collected by Mr. F. Spry [896]. 



Horizon. — Silurian (Melbournian). 



Genus Stropheodonta, J. Hall. 



Sub-genus Lepiosirophia, Hall and Clarke. 



Stropheodonta (Leptostrophia) alata, sp. nov. 

 (PI. XI., Figs. 6, 7). 



Specific characters. — Shell semi-circular, broadly rounded 

 anteriorly, cardinal margins produced and alate at the extremities ; 

 width greater than the length, valves depressed plano-convex. 

 Hinge line nearly straight. Denticulations of the cardinal area 

 extending to more than one half the entire length of the hinge. 

 Impression of posterior adductors strong, with a finely grooved 



1 See Hall and Clarke, op. cit., pi. iv., 1., figs. 3-16. 



