An Account of the Deep-sea Madreporaria collected by the "Royal Indian 

 Marine Survey Ship "Investigator" By A. ALCOCK, 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. Inti-oduction. 



2. The Geographical Distribution of certain Indian Deep-Sea Corals, and the evidence 

 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. INTRODUCTION. 



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 Tra van- 

 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- 



