Victorian Fos^'Us, Part XVI. 101 



.■Silurian (Melbouiniaii) of Suutli Yaii;i. Vittniiji. In (lutliue 

 S. plicatella very nearly resembles Bai raiidL's " Dixvnxi " pJivo^aS 

 from stages F and O (Lower Devonian) of Hranik and Konieprus in 

 Bohemia. Tliat form, liowevei'. is a true Or}>iculoidea, having a 

 posterior foramen, as well as merely finely concentric ornament. 



Occurrence. — Silurian (Yeringian). In grey nnidston'e : Van 

 Y'ean, Victoria. Presented by A. J. Shearsby, Esq.. F.H.M.S. 



Fam. Craniidae. 



(xenus Crania, Retzius. 



Crania piilc]iell()i<jfx, sp. nov. Plate X., figs. 2a, h. 



Description. — Slieil small, subpentagonal, slightly wider than 

 long (length measured post-anteriorly). Free valve depressed limpet- 

 shaped ; the apex situated a little towards the posterior margin. 

 Posterior margin short, straight, rather sharply angulated at the 

 extremities; thence the margin slopes steeply towards the rounded 

 and broad anterior margin. Surface of free valve furrowed with 

 concentric growth-lines and depressions, and having a variable 

 series of moderately-fine radial riblets converging to the apex. 

 Between the primary sharp and salient riblets there is a second 

 system of fine striae, commencing some distance from the vertex, and 

 extending to the margin of the valve. 



Measurements. — Length, 4.5 mm. ; width. 5.25 nim. ; approximate 

 height, 2.5 mm. 



Observations. — Undoubtedly the nearest allied form to the above 

 is Crania pulchella, Hall and Clarke, ^ a species occurring in the 

 Lower Heidelberg, near Clarksville, New York State. The shell 

 is larger and more rotund in outline than C. pulchelloiffes. None 

 of the British species appear to approach the Australian form liere 

 described. 



Occurrences. — Found occasionally in the Silurian ( Yci-iiigian) 

 mudstone in the neighbourhood of Lilydale. Holotype (from Rud- 

 dock's Quarry) presented by W. J. Parr. Esq. 



Fani. STU()PHO>rEXiDAK. 



Genus Leptaena, Dahnan. 



Lejjfaena rhonihoi(Iali>i. Wilckens sp. Plate X., rtgs. 3-7. 



Conchitts rhoniboidalis, \Vilckens, 1769, Xachricht von seltenen 

 Versteinerungen, vorziiglich des Thierreichs, p. 79, pL viii., figs. 



1 Syst. Sil. Boheme, vol. v., 1879, pi. ci., figs, ii., 1-7. 



2 Pal. N. York, vol. viii., Pal. Brach., pt. i., 1892, p. 180, pi. ivH., fig. 3. 



