An Account of the Deep-sea Madreporaria collected by the Royal Indian 
Marine Survey Ship “ Investigator.’—By A. Aucock, M.B., C.M.Z.S., 
F.G.S., Superintendent of the Indian Museum and Professor of Zoology 
in the Medical College of Calcutta: formerly Surgeon-Naturalist to the 
Indian Marine Survey. 
CoNTENTS :— 
§ 1. Introduction. 
2. The Geographical Distribution of certain Indian Deep-Sea Corals, and the evidence 
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that they appear to offer of a former Open-sea connexion between the Mediterranean Sea and the 
Seas of India. 
§ 3. List and Descriptions of Species. 
§ I. Inrropuction. 
I include as Deep-Sea Madreporaria only such as have been dredged at a 
depth greater than 100 fathoms. 
Of these we have obtained, during the last ten years, only twenty-five 
species, of fourteen genera—a small number ; though it must be remembered 
that the deep-sea dredging operations of the “ Investigator” are quite minor 
incidents of the general practical work of the Survey. 
So far as our observations go we find that (speaking, of course, of “ deep ” 
forms alone), in the Indian Seas, Madreporaria occur in greatest abundance 
at a depth of between 400 and 600 fathoms, where the bottom temperature, 
speaking generally, has been found to range from about 48° Fahr. to about 
44° Fahr. Only on one occasion have we dredged corals in mass at a greater 
depth than this, namely at 1,000 fathoms, where the temperature was 38°6° 
Fahr. 
The sea in which corals have been found in the greatest abundance and 
variety is the narrow basin between the Laccadive and Maldive Islands on the 
west and the Malabar coast on the east. At one spot in this sea, off the 
Elicapeni Bank, at 1,000 fms. we dredged over two hundred specimens 
of a large new species of Caryophyllia ; and at another spot, off the Travan- 
core coast, at a depth of about 430 fms., Dr. A. R. Anderson, the present 
Naturalist on the ‘ Investigator,’ lately dredged ‘nearly half a ton of living 
and dead coral......such a haul I have never seen.’ The corals on this occa- 
