~~ 
THE 
GEOLOGICAL MAGAZINE. 
NEW. SERIES .@ “DECADE. Ill. VOLUN: 
No. VI.—JUNE, 1888. 
@ EG seN PAs Acer @ ae Se 
eee 
J.—On tHe Cuert anp Siniceous Scurists ofr THE Prrmo-Car- 
BONIFEROUS STRATA OF SPITZBERGEN, AND ON THE CHARACTERS 
OF THE SPONGES THEREFROM, WHICH HAVE BEEN DESCRIBED BY 
Dr. E. von DunikowskEl. 
By Grorce Jenntnos Hinpeg, Ph.D., F.G.S., ete. 
(PLATE VIII.) 
HORTLY after the publication of my paper “On the Organic 
Origin of the Chert in the Carboniferous Limestone Series of 
Jreland,” in the Gronogican Magazine’ last October, my friend 
Prof. G. Lindstrém, of Stockholm, sent me a hand-specimen of 
cherty rock from the Permo-Carboniferous strata of Spitzbergen, 
which, on examination with a hand-lens, could be seen to be nearly 
entirely composed of spicules of sponges irregularly intermingled 
together, in the same manner as in the cherty beds of the Yoredale 
series in Yorkshire, Wales, and Ireland. This striking illustration 
of the organic origin of chert from a quite unexpected quarter 
induced me to inquire for further particulars of the nature and 
thickness of the rocks from which the specimen came, and Dr. A. G. 
Nathorst, of Stockholm, not only supplied me with the needful 
information which is given below, but further sent me a box of 
specimens of the rocks in question, which were for the most part 
obtained by the Swedish Expedition to Spitzbergen in 1882, under 
his leadership and that of the Baron de Geer. Prof. Lindstrom also 
sent for my examination most of the fossil sponges obtai-d by this 
same expedition, which have been described by Dr. v. Du xowski;? 
and I propose in the present paper first to refer to the extent and 
the characters of the cherty rocks of Spitzbergen, and neat to treat 
of the fossil sponges from them. 
I may premise, however, that the specimens of cherty rock which 
I have examined have been in no wise selected on account of the 
presence in them of sponge-remains, since the origin of the rock 
from these organisms was not at all suspected at the time they were 
collected. The specimens were procured because they contain 
certain other fossils, such as Brachiopoda and Polyzoa, which have 
no special connection with the origin of the chert. 
The following sketch of the stratigraphical divisions of the 
1 Dec, III. Vol. IV. pp. 435-446. 
* Ueber Permo-Carbon-Schwamme von Spitzbergen, Kongl. Svenska Vetensk.- 
Akad. Handl. Bd. 21, No. 1, pp. 1-18, taf. ii. (1884). 
DECADE III.—VvOL. Y.—NO. VI. 16 
