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 + has recorded 
three or four species from the London Clay of Sheppey ; Dr. 
Riist has discovered two species in the flints of the Upper 
Chalk J and a few remains in coprolites from the Lias of 
Gloucester §; and Prof. Sollas ||, many years since, noted 
their occurrence in the Cambridge 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. Williamsonff 
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 CaLcisphcera\\. I have examined microscopic 
sections of limestones containing these 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 diffe- 
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 ‘ Palseontographica,’ Bd. xxxiv. p. 185. 
§ Ibid . Bd. xxxi. p. 278. 
|| Quart. Journ. Geol. Soc. vol. xxix. 1873, p. 78. 
5] Brit. Assoc. Report, Brighton, 1872, p. 126. 
** 1 Nature/ March 1877, p. 461 ; Ann. Rep. Chester Soc. Nat. Hist. 
1876-77, p. 10. 
ft Phil. Trans, vol. clxxi. (1880) pt. ii. p. 511. 
XX Ibid, p. 520, pi. xx. figs. 67-81. 
