304 PROFESSOR P. M. DUNCAN ON THE 
vision of Professor Wyville Thomson, Dr. Carpenter, and Mr. J. Gwyn Jeffreys, in the 
North Atlantic, afforded satisfactory evidence of the existence of a coral fauna in the 
deep sea, and in water of a very different temperature from that usually considered 
necessary for the Madreporaria; but it was not until 1869 that, under the same able 
direction, the systematic dredgings of H.M.S. ‘ Porcupine’ proved the existence of coral 
life at a depth of 705 fathoms’. 
A description of this dredging expedition was read before the Royal Society in 1870, 
by Messrs. Carpenter, Wyville Thomson, and J. Gwyn Jeffreys’, and a report on the 
corals* obtained by those naturalists, and intrusted to me for examination and descrip- 
tion, was read before the same Society March 24th, 1870. 
When the second expedition was preparing to start in 1870, under the same able 
guidance, particular requests were made to me to advise concerning the dredgings, so 
far as the corals were concerned. The employment of the “hempen tangles,” instead 
of the crushing dredge, had already commended itself to the superintendents of the 
dredging operations; and it was a satisfaction to find that by using these simple means 
a fine collection of specimens was obtained off the west and south-west coast of the 
Spanish Peninsula and along the Mediterranean coast of Africa, from depths which 
reached to 1095 fathoms. , 
All the information I have required has been freely given me by the three naturalists 
who were responsible for the dredgings, and also by M. Lindahl their assistant. 
Professor A. Agassiz and Count Pourtales were of great assistance to me by sending 
me their reports and also a collection of the specimens dredged up by them, so that I 
have been enabled to compare the North-Atlantic forms with the West-Indian and 
Floridan types. 
I have also had the advantage of examining the results of the dredgings conducted 
by Mr. Kent, of the British Museum, and of his assistance in comparing specimens. 
The majority of the specimens dredged up and entangled during the two expeditions 
of the ‘Porcupine’ were alive and in good condition; a few had been dead for some 
time and were covered with Sponges, Serpule, and Polyzoa. Specimens were not 
invariably obtained at every dredging; and it is evident that corals live here and there 
in patches, and that they mostly frequent rocky ground, although some species live in 
the Globigerine ooze. Fine muddy sediment appears to be unfavourable to coral life ; 
and many of the dead specimens which came up in the dredge were filled with it. 
It is somewhat remarkable that so many well-known species, especially of the Medi- 
1 Proc. Royal Society, 1870. 
2 W. B. Carpenter, F.R.S., Wyville Thomson, F.R.S., and J. Gwyn Jeffreys, F.R.S., ‘ Deep-Sea Researches,” 
Proc. Roy. Soc. 1870, vol. xviii. pp. 397-492, 
W. B. Carpenter, F.R.S., and J. Gwyn Jeffreys, F.R.S., ‘Deep-Sea Researches,” Proc. Roy. Soc. 1870, 
vol. xix. pp. 146-221. 
3 P, M. Duncan, ‘ Porcupine’-Expedition Madreporaria, Proc. Roy. Soc. 1870, vol. xviii. pp. 289-301. 
