9G 



The Lamellibranghs of the Older Ter- 

 tiary OF Australia. (Pakt I.) 



By Professor Ealph Ta.te, F.G-.S., F.L.S., &c. 

 [Bead October 6, 1885.] 



Plates II.— XII. 

 FAMILY OSTKEID.E. 



Gexus Osteea. 

 stjS'opsis of species. 

 I. Valves radially ribbed, spinose. 



II. Valves foliated or smooth- 

 Elongate ; beaks produced 

 Obloug ; beaks subspiral. 

 Broadly attached, with erect front 



SUBCiEHTS G-ETPHJ:A. 



Umbo of lower valve largely incurved. 



O. Tiyotis. 



O. Sturtiana.. 

 O. arenicola 

 i beaks de- 

 O. liippopus, 



G. tarda. 



Ostrea hyotis, Linn. Plate vi., fig. 5. 



Itef. — Eeeve, Monogr. Ostrea, t. 4, fig. 7. 



" Shell irregularly subquadrate, solid, armed with tube- 

 shaped spines standing out upon the angles of about seven large 

 folds ; auricles rather compressed foliaceous plicated." — Iteeve. 



I refer a very common oyster in the Middle Murravian series, 

 with some hesitation, to the above-named species inhabiting 

 the Indian Ooean ; the fossil, however, rarely exhibits tubular 

 spines, more generally broad foliaceous scales; in shape it 

 varies from subquadrate to semicircular and obliquely oblong j, 

 the plications usually angular, are sometimes rounded when it 

 approaches to O. imhricata, Lamk. In the absence of examples 

 of the fore-named living species, I refrain from separating our 

 fossil. 



Dr. K. Martin has figured, under Linnaeus' name, an oyster 

 from the Older Tertiary of Java,* a variety of which is oblong. 

 According to this author, the same species occurs in the Indian 

 Tertiary beds, whence it has been described as O. tuhifera, 

 Sowerby in Trans. Greol. Soc, v., tab. 25, fig. 19., 1837. 



Localities. — Calciferous sand rock, Kiver Murray-cliffs at 



* Die Tertiarshichten auf Java, p. 125, t. 21, figs. 1 and 2, 1880. 



