152 



or seven costse on the posterior slope tuberculated ; the inter- 

 vening sulci are about as wide as the ribs. 



Umbo obtuse, incurved, with a slight forward projection. 

 The front and post-dorsal margins about equally sloping ; the 

 posterior area is flattened, its margin obliquely truncated. 



Margin of the valves crenulated. 



Dimensions. — Antero-posterior diameter, 15 ; umbo-ventral 

 diameter, 16 ; sectional diameter of a single valve at about 

 one-third the length from the umbo, 5 millimetres. 



Locality. — The older beds at Muddy Creek, near Hamilton, 

 Victoria. 



Cardium cuculloides, Tate. 



Reference. — Trans. Roy. Soc, S. Aust., for 1885 ; plate xii., 

 fig. 14. 



Shell thin, smooth, trapezoidal, oblique, tumid, inequilateral ; 

 umbones oblique, incurved, narrow, considerably in front. 

 Anterior margin rounded ; ventral margin nearly straight, 

 oblique to the hinge line ; posterior margin obtusely truncated ; 

 posterior slope flattened, separated from the moderately convex 

 rest of the valve by an obtusely-rounded ridge ; dorsal line 

 arched. 



Surface ornamented by equidistant, incised radial lines, 

 about one millimetre apart at the front ; in theumbonal region 

 the sulci are about half the width of the flat ridges ; on the 

 lateral areas the sulci, though narrow, are deep and obliquely 

 striated ; the flat ridges are marked in the middle line by a 

 slight groove widening out at irregular intervals into elliptical 

 depressions. Inner margin of valve flatly ribbed. 



Dimensions. — Longitudinal diameter, 32 ; length from umbo 

 to posterior angle, 31 ; width, 30 ; thickness through both 

 valves, 20 millimetres. 



Locality. — Muddy Creek (J. Dennant!). 



This remarkable species may be placed in the section Papy- 

 ridce ot Swain son. 



Cardium antisemigranulatum, McCoy. 



Reference. — Protocardium antisemigranulatum, McCoy, Pal. 

 Victoria, Decade v., t. 44, figs. 2-3, 1877. 



Quadrately-oval, gibbous ; umbo elevated, incurved, and 

 directed forwards ; posterior slope with acute radial ridges, 

 closely set with conical tubercles; rest of the surface re- 

 gularly, concentrically, and radially striated. 



Dimensions. — Antero-posterior diameter, 40 ; umbo-ventral 

 diameter, 42 ; sectional diameter of a single valve, 16 milli- 

 metres. 



Localities. — Rare at Moorabool {McCoy); very rare in the 

 older beds at Muddy Creek (J. Dennant!). 



