153 



Cardita latissima, spec.nov. PI. x., fig. 5. 



Shell quadrately orbicular, very inequilateral, inflated ; um- 

 bones near tbe front, oblique, incurved ; anterior side short, 

 rounded ; acutely-roundly truncated and compressed pos- 

 teriorly ; ventral margin regularly arched. Surface with about 

 30 fine" laterally compressed scaly ribs, much narrower than 

 the flattish transversely striated interspaces. The ribs are 

 densely beset with erect lamellar scales, becoming somewhat 

 spinous on the posterior slope and thick on the anterior area. 

 Lunule short, cordate, shallow ; inner margin of valves coarsely 

 crenulated. 



In very young shells the ribs are much fewer, granulated, 

 but spinose on the posterior slope. 



Dimensions. — Length, 31 ; of posterior side, 23 ; width, 29 ; 

 thickness through both valves, 20 millimetres. 



Localities. — Very abundant Adelaide bore, and Blanche Point, 

 Aldinga Bay. 



This species in its ornamentation is similar to the young of 

 C gracilicosteita, but the shape is very different; it is less 

 globose than the recent G. abyssicola, Hinds, but the sculpture 

 is different. 



Cardita spinulosa, spec. nov. PI. ii., fig. 3. 



Shell rotundately heart-shaped, inflated, inequilateral; umbo 

 anterior, oblique, incurved ; radiately ribbed. Eibs, 22 ; 

 spinosely serrated, very narrow, laterally compressed ; inter- 

 spaces wide, densely and irregularly lamellosely wrinkled ; in 

 the umbonal region the interspaces and the ribs are minutely 

 granular. Inner margin of valves coarsely crenulated. 



Dimensions. — Length, 33 ; width, 31 ; length of anterior side, 

 9 ; thickness through both valves, 36 millimetres. 



Locality. — Blue clays, Schnapper Point, Hobson's Bay. 



Cardita polynema, spec. nov. Plate ii., fig. 7. 



Shell roundly-oblong, transverse, moderately inflated ; um- 

 bones anterior, oblique, incurved ; anterior side very short. 



Surface ornamented with 37 narrow compressed radial ribs, 

 about as wide as the interspaces ; ribs densely covered with 

 erect oval scales, except on the posterior and anterior slopes 

 where they are somewhat spinous. 



Dimensions. — Length, 18 ; width, 15 '5 ; thickness through 

 both valves, 11 millimetres. 



Locality. — Schnapper Point, Port Phillip. 



This species agrees in shape with C. gracilicostata., though 

 less produced anteriorly, but has more numerous and closer 

 ribs ; it is somewhat intermediate between that species and 

 €. scahrosa. 



