[Proc. Roy. Soc. Victoria, 31 (N.S.), Part I, 1918]. 



Art. v.— Ostracoda from the Upper Cambrian Limestone of 



South Australia, 



By FREDERICK CHAPMAN, A.L.S., &c. 



(Palaeontologist, National Museum, Melbourne). 



(With Plate IX.). 

 [Eead May 9th, 1918]. 



Sources of the Collection. 



In January, 1903, Mr. George Sweet, F.G.S., of Brunswick, 

 kindly placed a series of leperditioid fossils in my hands for descrip- 

 tion. The specimens, numbering about twenty-two, w^ere collected 

 by Mr. Sweet from the Upper Cambrian Archaeocifathina Limestone 

 .-at Curranmlka, South Australia. 



Subsequently, in January, 1906, Mr. Walter Hc^vchin, F.G.S., of 

 the Adelaide University, was good enough to send me a tablet of 

 -similar ostracodal remains from the same locality; and quite 

 recently he supplemented these with two others. These mounted 

 .specimens from the Adelaide Museum presumably included the two 

 forms mentioned by Prof. Ralph Tate in his paper, ** On the Cam- 

 brian Rocks at Curramulka."! and to which reference will be found 

 in the descriptive part of tliis paper. 



Generic Affinities of the Species. 



After a rather prolonged study of these difficult forms I have 

 concluded that they represent both Leperditia &r\d IsocJiilina. The 

 former genus is more usually met with in Ordovician and Silurian 

 strata, and occasionally in Devonian and Carboniferous beds, but is 

 not unknown from the Upper Cam.br i an notwithstanding that E. 0. 

 Ulrich in Eastman-Zittel2 gives the range '* Ordovician to Carboni- 

 ferous." That the genus Leperditia was already established in 

 Upper Cambrian times is seen from tlie following references : — 



In the Calciferous Sandstone of Grande Isle, Grenville and 

 Ilawkesbury, Canada, which is equivalent to the Tremadoc Slate of 

 the Upper Cambrian, Leperditia ca?iade?)f<is occurs, together with 

 Beyrichia lof/aiii and Isochilina ottaira . Leperditia anna is found 

 in similar beds in St. Ann, Canada. 3 



1 Trans. Roy. Soc. South Austr., vol. xv., 1892, p. 187. 



2 Text-book of Palneontologfv. vol. i., 2nd ed., 1913, p. 737. 



3 See Rupert Jones. Ann. Ma<(. Nat. Hist., ser. .S, vol. i., 1858, pp. 244, 247. 



