148 



Dimensions. — Length, 8-5 ; width, 7"5 ; thickness through 

 both valves, 3 millimetres. 



Locality. — Calcii'erous sandstones, E. Murray Cliffs, near 

 Morgan. 



FAMILY ASTARTID^. 

 Genus Micromeeis, Conrad. 



SYNOPSIS OF SPECIES. 



Ornament o£ fimbriated, imbricating lamellae. M. rugosa. 



Ornament of radial ridges and simple folds. M. radiata. 



Micromeris rugosa, spec. nov. Plate x., fig. 11. 



Shell trigonal, compressed, with produced somewhat at- 

 tenuated rather straight umbones, equilateral ; anterior and 

 posterior slopes straight, inclined at an acute angle ; ventral 

 martyin rounded ; inner margin of valves distantly crenulated. 

 Lunule narrow, not deeply impressed. Surface crowded with 

 thin imbricating lamellae ; the edges of the lamellae varying 

 from simple to thickly fimbriated, the fimbriations correspond- 

 ing with rounded depressed radial riblets. ^ 



Dimensions. — Length, 3 ; width, 3-5 millimetres. 



Locality. — Lower beds, Adelaide bore. 



Micromeris radiata, spec. nov. Plate x., fig. 12. 



Shell trigonal, slightly convex, with produced rather straight 

 umbones, equilateral, ventrally rounded ; inner margin of 

 valves distantly crenulated. Surface smooth, shining, radially 

 ribbed, and concentrically ridged or coarsely striated. Um- 

 bones in contact, bounded before and behind by a deep ellip- 

 tical depression, angulated on the margin. 



Dimensions. ~LQngt\i, 4-5 ; width, 4-5 ; thickness through 

 both valves, 2d millimetres. 



Localities. — ^Yery common in the lower beds, Blanche Point, 

 Aldinga Bay, and Adelaide bore. 



Gouldia lamellata, spec. nov. Plate ii., fig. 17. 

 Shell subtriangular to subquadrangular, compressed or 

 moderately convex ; umbones anterior, rather elevated and 

 acute. Surface with about twenty thin, elevated, concentric 

 lamellae, and stri» of growth. Inner margin of valves with 

 large, close crenulations. The shell differs in shape, in the 

 amount of compression, and in the number of the lamellar 

 folds ; but one set of characters is not correlative with another 

 set, so that the variations are individual, and not specific. The 

 subquadrangular forms have a close resemblance to a Ckione, 

 allied to Venus Allporti, T. Woods, occurring in the same 

 beds. 



