149 



two divergent laminar teeth, one on each side of a broad trian- 

 gular cartilage pit, of which the posterior is large and oblique, 

 and the anterior very small. The right valve has a lamellar 

 projection of the dorsal margin on either side of the cartilage- 

 fossula. 



Dimensions. — Antero-posterior diameter, 65 ; umbo-ventral 

 diameter, 5 ; sectional diameter, 3 millimetres. 



Localities. — Upper beds at Muddy Creek ; oyster beds of the 

 River Murray Cliffs at the Nor'-AVest Bend. 



FAMILY CHAMULE. 

 Chama lamellifera, Tenison- Woods. Plate xiv., figs. 5a—5&. 



Reference. — Proceedings of Royal Society of Tasmania for 

 1876, p. 114. 



Surface of both valves ornamented with distant, thin, ir- 

 regular, sometimes projecting lamella*. The lamellae are finely 

 radiately ridged and striated ; interspaces between the lamellae 

 concentrically striated. Rarely exceeding 20 millimetres of 

 diameter. 



Localities. — Table Cape (It. M. Johnston !) ; older and 

 younger beds at Muddy Creek ; clays at Schnapper Point ; 

 well sinking, Nine-Mile Camp, near Nor'-West Bend ; clayey 

 sands, Adelaide bore. 



Chamostrea albida, Lamarck. 



Reference. — Animaux sans Yertebres, vol. vi., p. 96, 1819. 



Synonym. — ft crassa, Tate, Proc. Roy. Soc, Tasmania, for 

 1884, p. 228. 



1 do not hesitate to refer an example of a large valve ob- 

 tained by Mr. Dennant from the Muddy Creek beds to the 

 above-named species of the peculiar Australian genus. A left 

 valve collected by Mr. R. M. Johnston at Table Cape was 

 erected by me into a distinct species, but I think now on 

 insufficient grounds. 



Right very convex, keeled, attached by its anterior side ; 

 umbo anterior subspiral ; left valve flat ; surface smooth, with 

 distant growth-lines. About two inches diameter. 



FAMILY VERTICORDIIDJE. 

 Verticordia rhomboidea, spec. nov. Plate xiv., fig. 4. 

 Considerably inflated, rhomboid, very inequilateral. Umbo 

 inflated, much curved over towards the front, and situated quite 

 at the anterior end ; the ventral margin nearly straight, the 

 dorsal margin arched, making with the straight posterior margin 

 an obtuse angle ; anterior margin at first concave, forming a 

 rounded somewhat produced angle with the ventral margin. 



