189 



Carditella multilamella, spec. nov. Plate xx., fig. 17. 



This species is similar to C. lamellata, but it differs by its- 

 ovately-oblong form, and the stoutish recurved, numerous 

 lamellae. It might be overlooked for the fry of Chione 

 Cainozoica. 



Dimensions. — Antero-posterior diameter, 3 ; umbo-ventral 

 diameter, 25 ; sectional diameter of one valve, "75 milli- 

 metres. 



Locality. — Lower beds at Muddy Creek. 



Cardita solida, spec. nov. Plate xx., fig. 18. 



Subtrigonally cordate, very thick, moderately convex, sub- 

 equilateral, both ends obtusely rounded. The dorsal margin is^ 

 considerably oblique on both sides of the prominent umbo, 

 which is well curved over towards the front ; the lunule is- 

 depressed, cordiform ; the ventral margin is much curved. It 

 is ornamented with eighteen radial ribs, which are stout, 

 rounded, and almost smooth ; the interspaces are a little 

 broader than the ribs, transversely stoutly lirate. Margin 

 strongly plicated. 



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

 diameter, 6'5 ; sectional diameter of one valve, 2 5 milli- 

 metres. 



Locality. — Upper beds at Muddy Creek (J". Dennant !) . 



This new species has some affinity with the Tasmanian 

 C. Gunnii, Desh., and C. himaculata, Desh., but the shape is 

 different, in which particular, however, it agrees with G. Bed- 

 domei, E. A. Smith, differing from it by the fewer non-nodulose 

 ribs. 



Cardita calva, spec. nov. Plate xx., fig. 14. 



Ovately-subtrigonal, subequilateral, moderately depressed; 

 rounded anteriorly, truncatedly rounded posteriorly. Umbones 

 prominent, acute, slightly incurved ; lunule depressed, broadly 

 lanceolate, smooth, with well-defined margins. 



The umbonal area is smooth, with excentric distant sulca- 

 tions, the rest of the surface of the valve radiately ribbed ; 

 ribs 20, covered with thick closely-set granulations ; the inter- 

 spaces on the medial part of the surface are linear or almost 

 obliterated, becoming wider towards the anterior and posterior 

 margins. 



Dimensions. — Antero-posterior diameter, 5'25 ; umbo-ventral 

 diameter, 5' ; sectional diameter of one valve, 1*5 millimetres. 



Localities. — Older beds, Muddy Creek; well-sinking on 

 Cooke's Plains, east of Lake Alexandrina. 



The nearest ally to this species is C. compacta, Tate, but is- 

 slightly different in shape, and depressed, the gross ornament 

 and smooth umbo especially distinguish it. 



