302 GKTPH^A. 



rugosely ridged, growth-lines distant, except near the ventral 

 margin in the adult ; hinge small, triangular, transversely striated. 

 Right valve flat, almost the same size as the left ; concentric 

 growth-lines distant. 



Dimensions. — Height 80 mm. ; length 82 mm. 



Form, and Loc. — Miocene : Napier, New Zealand. 



L. 10518. Several perfect, double-valved examples. 



Sir James Hector Coll. 



Ostrea, sp. 



42682. Imperfect left valve of a new species, closely radially 

 ridged on the exterior and interrupted by frequent irregular growth- 

 lines, anterior margin serrate; from the Tertiary of (locality ?) 

 South Australia. Presented hy the Governors of Adelaide Museum. 



L. 348. Right and left valves of young Ostrea, indeterminable ; 

 from the Tertiary of Bairnsdale, Victoria. 



Presented hy W. H. Grigson, Esq. 



L. 10527. Large specimen of Ostrea, allied to 0. arenicola, 

 Tate ; Miocene (?), Parimoa, New Zealand. W. B. B. Mantell Coll. 



Genus GRYPHiEA, Lamarck. 

 [Syst. Auim. sans Vert. 1801, p. 398.] 



Yalves of unequal length, the left often free in the adult; 

 umbo of left valve incurved, often oblique; right valve flat or 

 concave, short. 



Type. — Gryphcea angulata, Lamarck. 



Gryphsea tarda, Hutton. 



1873. Gryplma tarda, Hutton, Cat. Tert. Moll. N.Z. p. 35. 

 1886. Gryphcea tarda, Tate, Trans. Roy. Soc. South Aust. vol. viii. p. 98, 

 pi. vi. figs. 2a-i. 



Shell irregular in outline, general form ovate ; umbo of left 

 valve curved inwards and bent forward ; right valve rather concave 

 and much smaller than the other. Hutton says : " Area broad, 

 triangular, distinctly transversely striated ; muscular impression 



