SPONGE-EEMAINS IN THE TERTIAEY OF NEW ZEALAND. l77 



On the Sponge-remams in the Lower Tertiary Strata near 

 Oamaru, Otago, New Zealand. By Gr. Jennings Hinde, 

 Ph.D., and W. Murton Holmes. (Communicated by 

 W. Percy Sladen, Sec. Linn. Soc.) 



[Eead 4th February, 1891.] 



(Plates VII. -XV.) 



Tntboditction. 



The Sponge-remains described in this paper were obtained 

 from beds of siliceous or siliceo-calcareous material of some 

 considerable thickness, which are exposed ia several localities 

 in the vicinity of the town of Oamaru, on the east coast of the 

 South Island of New Zealand. Specimens of this material were 

 first sent to this country, in the early part of 1886, by Capt. F. 

 "W. Hutton, F.Gr.S., Professor of Greology at Christchurch, New 

 Zealand, who described it in a letter to Prof. Rupert Jones, 

 F.E.S., as a Eadiolarian ooze containing large quantities of 

 spouge-spicules and radiolarians. Subsequently other examples 

 ot" the rock were brought over by the late Sir J. v. Haast and 

 exhibited at the Colonial Exhibition at South Kensington, and 

 fragments of it were freely distributed to those interested in 

 microscopic research. On examination, the rock proved to be 

 extraordinarily rich not only in the organisms referred to by 

 Capt. Hutton, but in diatoms as well, and these last-named forms 

 have since been carefully worked out and described by Messrs. 

 Grrove and Sturt in the Journal of the Quekett Microscopical 

 Club *. These authors have enumerated 283 different forms, 

 107 of which are new species or varieties. From the great 

 abundance and variety of these organisms, the beds have been 

 regarded as a diatomaceous deposit, but it is evident that the rock 

 contains such a commixture of sponge-remains, radiolarians, and 

 diatoms, that it can just as appropriately be designated after one 

 of these forms of life as after another. 



From information supplied by Capt. Hutton, and from an 

 account of the deposit given by Mr. H. A. de Lautour in the 

 Transactions of the New Zealand Institute t, it appears that the 

 principal exposures of this siliceous rock ai^e Cormack's siding in 



* Ser. 2, vols. ii. & iii., 1886-87. 

 t Vol. xxi. 1888, pp. 293-311, pis. sviii.-xxiii. '■: 



LINN. JOrRN. — Z00L0(ilY, TOL. XXTV. 13 



