157 



Waldheimia pectoralis, spec. nov. PL vii., figs, la— d. 



Shell elongate to elongate-ovate, longer than wide ; greatest 

 width near the middle \ valves very unequal, lateral margins 

 strongly curved, deflected. Brachial valve strongly convex 

 longitudinally ; at the anterior third flattened ; with a shallow 

 sulcus proceeding from the beak and widening out to the front 

 margin, which is sinuated or slightly plicate. Peduncular valve 

 very convex and deep, with a flattish triangular area corres- 

 ponding with the sulcus of the other valve. 



Loop reaching to near the front margin ; lamellae slender, 

 with a slight curve towards the central line ; reflected portion 

 opening out to three times the width of the other ; septum high, 

 extending for three-sevenths of the length of the brachial 

 valve. 



Beak produced sub-erect, truncated by a very small foramen, 

 and separated by a large crescentric deltidium of one piece, 

 which is corrugated transversely to its length. Surface of the 

 shell with concentric lamellae of growth ; densely and minutely 

 punctated. Immature shell with a shallow sulcus extending to 

 the front margin, which is depressed and sinuous. 



Dimensions — Length, 225 inches ; breadth, 1'8 ; thickness, 

 1*1 inch. 



Locality and Horizon. — Xot uncommon in the glauconitic 

 limestone, which forms the base of Blanche Point Cliff, 

 Aldinga. 



Waldheimia (?) sufflata, spec. nov. Plate vii., fig. 3 ; plate viii., fig. 4. 



Shell subovate, greatest width about the middle ; lateral 

 margins convex in the middle, becoming straight or slightly 

 bisinuated (rarely biplicate) towards the narrow rounded front. 

 Test thick, surface smooth, with numerous moderately strong 

 lines of growth. Shell structure minutely and closely punctate, 

 as viewed under a lens. Peduncular valve A r ery convex in a 

 longitudinal direction, and regularly convex transversely. 

 Beak strongly incurved, slender, fox'amen minute. Deltidium 

 of one piece, broadly triangular and deeply concave. Brachial 

 valve very convex, faintly impressed or flattened medially, 

 becoming gradually depressed in the middle towards the some- 

 what narrowed front. 



Septum a little less than half the length of the valve. Loop 

 unknown. 



Dimensions. — Length of a large specimen, 265 inches ; width, 

 18 ; depth, 1-6. 



Observations. — This species has the minute foramen and 

 slender beak of W. pectoralis, but in other respects the 

 differences are very great. Some examples partake of the 

 shape of certain varieties of W. Corioensis, but despite this 



