286 Proceedings of the Royal Physical Society, 
tentacles, and showing through their parietes white longi- 
tudinal ridges, which indicate the number of zooid elements 
of which they are composed. 
In the natural history of this remarkable zoophyte there 
are other points of peculiar interest, which, having already 
described, I need only mention here : the slow development 
and unique shape of the planuloid larva ; the powerful 
muscular structure of the polyps, especially the spiral ones, 
the office of which last has yet to be discovered ; and the 
intimate sympathy and combined action which subsist be- 
tween the various parts of the whole animal. 
III. Notes on Deep Sea Soundings. By E. W. Dubuc,* M.D., R.N. 
Communicated by Mr James B. Davies. 
The deposits now forming at the bottom of the ocean 
possess a peculiar interest from a zoological as well as from 
a geological point of view, especially when we consider the 
importance of the natural processes upon which they are 
capable of throwing light. 
It is only of late years, however, that we have been en- 
abled with any degree of accuracy to sound the vast depths 
of the ocean, to map out the varying configuration of the 
solid substrata, and to examine into the nature of the latter. 
We owe this in great measure to the invention of an im- 
proved form of sounding apparatus by Mr Brooke of the 
United States Navy. 
Specimens thus obtained from great depths were sent to 
Professor Ehrenberg of Berlin, and Professor Bailey of New 
York. The latter submitted samples of the sea bottom from 
that part of the North Atlantic which covers the telegraph 
plateau to microscopical examination, and found them to be 
filled with minute organisms, and to contain neither sand 
nor gravel. The organisms were mainly calcareous, consist- 
ing of the shells of various genera of Foraminifera [Poly- 
thalamia of Ehrenberg) . There were besides a small number 
of the siliceous shields of diatoms. 
^ I observe, with much regret, a notice of the death of Dr Dubuc on board 
TI.M.S. Cossack, at the Cape of Good Hope, on the 10th of January 1862, at 
the early age of 24. — J. B. D. 
