[Proc. Roy. Soc. Victoria, 26 (N.S.), Part II., 1914. 



Ari'. XXI. — Description of New and Rare Fossih obtained 

 by Deep Boring in the Mallee. 



Part TT. — Mollusca. 



F. CHAPMAN, A.L.S. 



(Palaeontologist to the National Museum), 



AND 



C. J. GABRIEL. 



(With Plates XXI\ .-XXVIII.) 



[Read 13th November, 1913]. 



MOLLUSCA. 



Class PELECYPODA. 



Fam. NFCULIDAE. 



Genus NUCULA, Lamarck. 



NucuLA OBLiQUA, Lamarck. 



Nucula ohliqua, Laniarck, 1819, Aniin. sans Vert., vol. vi , 

 pt. i., p. 59. Hedley, 1902, Mem. .Austr. Mus. Sydney, 

 No. iv.. p. 292. 



In the present borings A. ohliqua, Lamarck is represented by 

 some identifiable fragments and one perfect valve. The latter, 

 together with numerous specimens in the Dennant collection, bears 

 out our conclusion that in the oldest of our Tertiary beds the 

 ancestors of the living species are represented by a more depressed 

 shell, of thinner build, and more acute at the umbones ; inter- 

 mediate forms are found in the Janjukian series at Table Cape; 

 whilst in the Kalimnan beds of Grange Burn and elsewhere, the 

 eame species had already attained characters seen in the living 

 N. obliqua. 



Disfributio?i.— Bore 8. 165-180 feet. Bore 9. 254-256 feet. 



