118 



named species oi: Australian seas, that it is with some hesita- 

 tion I venture to separate them. However, L. Bassii may be 

 distinguished by its flatter shell, less inflated beaks, less pro- 

 duced anteriorly, and by its narrower hinge line, whilst the 

 ribs are usually more rounded and the anterior ear obsolete. 



Taking two examples of about the same size, the following 

 measurements will forj:iulate some of the above-mentioned 

 differences : — 



L. Bassii L. squamosa 

 Antero-dorsal diameter ... 41 89 millimetres 



Lateral diameter 33 35 



Breadth of hinge 10 13 



The New Zealand Older Tertiary species, L. multiracliata 

 and L. paJeafa, Hutton, are closely related to L. Bassii, but in 

 them the ribs are wider apart. 



Lima polyactina, spec. nov. PI. viii., figs. 4a — 4c. 



Shell minute, ovate-trigonal, veutricose, nearly equilateral ; 

 lateral and ventral margins regularly convex, attenuated to- 

 wards the dorsal line, ornamented with numerous (about 70) 

 depressed radial ribs, smooth or minutely-scaly, interstices- 

 narrower than the ribs, punctatedly impressed. Hinge line 

 very short, almost wholly anterior ; umbos erect, acute, 

 divergent; lunule-area deeply impressed; anterior auricle 

 minute, triangular, posterior obsolete. 



Dimensions. — Yentro-dorsal diameter, 1; lateral diameter,. 

 6 millimetres. 



Locality. — Adelaide bore, three examples {R.T.). 



Lima linguliformis, spec. nov. PL iii., figs, la—lh. 



Shell oval, sub-compressed, equivalve, almost equilateral; 

 valves gaping in front, ornamented with flattened, slightly 

 wavy, inconspicuous ribs which radiate from the longitudinal 

 centre-line ; ribs obscurely granose-nodulose towards the 

 ventral margin, the narrow interstitial furrows coarsely punc- 

 tated. Anterior auricle, with the outer margin thickened and 

 everted ; posterior auricle obsolete. 



Dimensions. — A^entro-dorsal diameter, 19 ; lateral fliameter, 

 15 ; thickness through both valves, 6 millimetres. 



Locality. — Muddy Creek {R.T.) ; Schnapper Point, Port 

 Phillip Bay {R.T.). 



This fossil species is allied to L. scahra, Born., and L. tenera, 

 Chem., by its divaricate sculpture, and approaches the latter 

 in shape, but differs in its oval outline and imperfect posterior 

 auricle. 



