122 



Dimensions. — Young example, pi. ix., fig. 9. Length of hinge, 

 37 ; greatest length measured from umbo to the post-ventral 

 margin, 37 millimetres. Average-sized adult specimens mea- 

 sure about 60 millimetres in the transverse diameters. 



Localities. — Muddy Creek, Hamilton (young examples only) ; 

 oyster-beds. North-west Bend Head Station, near Morgan, 'on 

 the Eiver Murray (adult examples only). B. T. 



Vulsella laevigata, spec. nov. Plate iii., figs. 3a— Sb. 



Eight valve narrow oblong, attenuated dorsally and rounded 

 ventrally, posterior side nearly straight, anterior side somewhat 

 arched; greatest width in 'the dorsal-third; umbo a little 

 swollen and elevated, not divergent from the hinge. Surface 

 irregularly concentrically lamellose, especially in the umbonal 

 region. Hinge-line short ; but the ligamental socket propor- 

 tionately long, triangular, erect. 



Dimensions. — Length .11, height 29 millimetres. 



Loccdiiy. — Glauconitic limestone at the base of "Witton 

 Bluff, near mouth of the Eiver Onkaparinga. 



By the absence of crenulated striae or scales, and by its form, 

 it approximates to F. deperdita of the European Eocene, but 

 that shell is broader with diverging umbos ; its resemblance to 

 F. angustata, Deshayes, of the Parisian Eocene is very close, 

 from which the present species differs by the large, straight, 

 ligamental pit. 



Perna, sp. ind. 

 ^ LocalHy. — "Witton Bluff, at the mouth of the Eiver Onkapa- 

 ringa. A cast of a large species apparently identical with an 

 undescribed species from the "Trelissick 'Group," New Zea- 

 land. 



SUB-FAMILY PINNIIKE. 

 Genus Pi^'Na. 

 Valves convex, longitudinal ribs with erect scales. 



P. semicostata. 

 Yalves acutely angulated, longitudinal ribs without scales. 



P. sp. 



Pinna semicostata, s])ec. not\ Plate xii., fig. 9. 



Triangular, elongate, slightly sinuated at the byssal region ; 

 valves very convex with abrupt sides, the dorsal half with 

 rather close obsolete longitudinal ribs (about ten) raised into 

 close short semi-cyclindrical scales ; the ventral half with 

 strong concentric folds. 



Dimensions. — Length of dorsal margin 130, width Qo, 

 greatest thickness through both valves 43 millimetres. 



Localities. — Oyster banks, Adelaide and Aldinga Bay. 



