46 Dr. G. J. Hinde on Radiolaria from the 



Lately Dr. Rust * has announced the occurrence of Radiolaria 

 in all the principal divisions of the Palseozoic series, but a 

 detailed description of the forms has not yet appeared. 



Very few Radiolaria have been as yet noticed from the 

 rocks of this country. Mr. W. H. Shrubsole f has recorded 

 three or four species from tlie London Clay of Sheppey ; Dr. 

 Riist has discovered two species in the flints of the Upper 

 Chalk \ and a few remains in coprolites from the Lias of 

 Gloucester §; and Prof. Sollas ||, many years since, noted 

 their occurrence in the CamlDridge Greensand, but he has not 

 yet described the species. The presence of Radiolaria in the 

 Coal-measures of Lancashire^ and in the Carboniferous Lime- 

 stone of North Wales** has been reported from time to time ; 

 but the minute spherical bodies in the Coal-measures known 

 as Traquairia have been shown by Prof. W. C. WiUiamsonff 

 to be vegetable structures, and the same author considers that 

 the objects in the Carboniferous Limestones, presumed to be 

 Radiolaria, are really composed of carbonate of lime, and he 

 has named them Calc{sph(era\\. 1 have examined microscopic 

 sections of limestones containing th^se organisms, and I 

 agree with Prof. Williamson that there is no evidence to 

 support the view that they were originally siliceous. 



The apparent rarity of Radiolaria in the later Palaeozoic 

 and more recent strata in this country renders their occurrence 

 in such great abundance in this Ordovician chert still more 

 remarkable. Considerable attention has been paid lately to 

 the nature of the chert and allied siliceous rocks of the ditFe- 

 rent British sedimentary formations, but hitherto no other 

 siliceous organisms than sponges have been found in them ; 

 and this Scotch chert is the first instance in which in our area 

 this description of rock has been traced to the skeletons of 

 other organisms than sponges. A large series of sections of 

 chert from different formations has come under my own notice 

 of late years, but in only one instance, that of a chert-bed in 

 the Carboniferous Limestone of Flintshire, have I met with 

 Radiolaria, and in this there were only a few individuals of a 



* Jahresb. d. naturhistor. Gesellsch. zu Hannover, 1883-87 (1888), 

 pp. 49-56. 



t Quart. Journ. Geol. Soc. vol. xlv. (1889) p. 121. 



j ' Palseontogi-apbica/ Bd. xxxiv. p. 185. 



§ Ibid. Bd. xxxi. p. 278. 



II Quart. Journ. (ieol. Soc. vol. xxix. 1873, p. 78. 



•(] Jirit. Assoc. Report, Brighton, 1872, p. 126. 



** ' Nature,' March 1877, p. 461 ; Ann. Hep. Chester Soc. Nat. Hist. 

 187C-77, p. 10. 



tt Pliil. Trans, vol. clxxi. (1880) pt. ii. p. 511. 



\l Ibid. p. 520, pi. XX. figs. 67-81. 



