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On a Fossil Marine Diatomaceous Deposit from Oamaru, 



Otago, New Zealand. 



By E. Grove and G. Sturt, F.F.R.M.S. 



PART I. 



Plates XVIII, XIX. 



(Taken as Read July 23rd, 1SS6.J 



This very interesting deposit was first brought to our notice by 

 H. Morland, Esq., a member of this Club. We are indebted to 

 him not only for the first supply of the material, but also for the 

 assistance he has rendered in furnishing many beautiful picked slides 

 of the rarer forms. For a further supply of the deposit we have to 

 acknowledge the kind aid of Sir Julius von Haast, K.C.M.G. The 

 deposit consists mainly of diatomaceous remains, with a small pro- 

 portion of Radiolaria, and Sponge spicula. Further information is 

 necessary before the geological age and position of the deposit can 

 be ascertained, but from the information at present before us, we 

 understand that it was found in the Cave Valley, Oamaru, situated 

 immediately beneath a series of Limestone strata known as the 

 Otatara Limestone series belonging to the Lower Tertiary (Oligo- 

 cene) age. There is a remarkable similarity between this deposit 

 and the well-known one from the Cambridge Estate, Barbadoes. 

 Several of the forms occurring here have, we believe, hitherto only 

 been met with in that deposit. The family BiddulphiEe, as in the 

 Barbadoes, is strongly represented by the genus Triceratium, 

 which, for the sake of convenience, we still retain. Of this genus 

 alone we have noticed over 30 species or distinct varieties. There 

 also seems to be a connection between the Simbirsk deposit and 

 this, as some of the Simbirsk forms occur with only a slight varia- 

 tion. Several of the species, notably those of Mastogloia and 

 Amphora, still exist in the Indian Ocean. 



For the drawings from which the plates are engraved we are 

 indebted to the valuable aid of A. M. Warner, Esq., of Saltburn- 

 by-Sea, and H. F. Hailes, Esq., our editor, to both of whom we 



