elxx Proceedings of the Asiatic Society of Bengal. [N.S., XV, 
Schizomeris, Draparnaldia, Sirogonium, and Spirogyras with replicate 
end 
s, etc., etc. 
i; smids, both filamentous and solitary forms, are v mon 
uring the mensoon seasons, especially in rain water seule; ditches and 
paddy-fields, 
1 
1. Clathorocystis is a dominant plankton form in many open Seg : 
Raph is — adapted hy stand the strong tropical illumination. But during 
the 
oon season it dies out in large quantities owing to the Wak 
ote’ areninnet ion. 
Section of Geology. 
President—L. Lricu Frermor, O.B.E., D.Sc., A.R.S.M., 
F.A.S.B., 'P. GS 
Presidential Address. 
SomE PROBLEMS OF ORE GENESIS IN THE ARCHAEAN 
or InpIA 
(With Plate IT.) 
CONTENTS. 
Page 
I. Introduction elxx 
II. The origin and relationships of the Siehisek i caabiona 
of India . 1xxii 
iil. Ore Sepositiodl in ~ a Rechscdas of T eee 
A. Syngenetic sedimentary oe dap of the Dhar- 
wars ay elxxix 
1. Iron-or ne 2 ae te oy aiexix 
2: Mingits nese-ores se .. elxxxi 
B. Syngenetic, igneous ore ; ducal ia: .. elxxxiii 
C. Epigenetic ore-deposits due to granitic intrusions 
1. Singhbhum a a < elxxxviii 
2. Sikkim xci 
3. Kolar exci 
IV. Summary 
l. Inrropvuction. 
At a scientific meeting the scope of a paper is usually 
circumscribed by the necessity of producing the facts concern- 
ing the views, hypotheses, or theories advanced, or is devoted 
to describing facts of Nature. But a presidential address may 
regarded as freed to a certain extent from these necessary 
restrictions, éording the author a — opportunity of 
discussing one of the broniber aspects of his science. Accord- 
and the privilege of placing before you, a summary of ideas 
resulting from considerable experience of the most ancient 
rocks of India 
