Tertiary.] PALAEONTOLOGY OF VICTORIA. IMollusca. 



with fewer sjiinose ridges on the attached valve, and having them 

 quite as numerous on the upper valve as on the attached one, or 

 even more so ; the ridges with large spines are also much more 

 prominent in the Victorian species. 



Occurs in great abundance in Miocene Tertiary sandy strata of 

 Bird Rock BluiF (A'^ 23) near Geelong. More rare in the cream- 

 colored Miocene limestone of Boggy Creek, six miles from Sale, 

 Gijipsland. 



Explanation of Figuhes. 



Plate XXXVIII.— Fig. 1, right or attaclied valre, natural size, inner view, showing muscular 

 impressions and pallial scar, large cardinal area with its median grooTe extending to the 

 internal triangular cartilage pit, flanked on each side by a large cardinal tooth, each of which on 

 its outer side has the deep pit for the teeth of the opposite valve. Fig. la, external surface of 

 same specimen, natural size, showing the usual concentric lamellar character near the beak and 

 on the sides. This individual shows a rather greater number of the large spiuose ridges than 

 usual. Fig, 16, portion of large ridge and adjacent smaller ones from the side near the beak, 

 magnified. Fig. Ic, small intermediate ridging near the middle margin, magnified. Fig. Id, side 

 view of same specimen, natural size. 



N.B. — All the figures ou this plate have been unfortunately reversed in the lithographing. 



Frederick McCoy. 



C 28 ] 



