DISTRIBUTION OF COEALS. 243 



dredged off the Bermuda islands in thirty fathoms of water ; off the 

 Virgin islands in three hundred and ninety fathoms ; off Martha's 

 Vineyard in two hundred and fifty; and off the coast of Japan 

 in twenty-nine hundred. Deltocyathus Italicus has been obtained 

 off the Bermuda islands from depths of two hundred and ten 

 hundred and seventy-five fathoms, respectively ; off the West In- 

 dies from a depth of seventy-five fathoms ; off the coast of Cape 

 Cod from one hundred and forty-two; and in the South Pacific 

 (latitude 32° 36', longitude 137° 43' west) from a depth of twenty- 

 three hundred and seventy-five. The total number of genera 

 which have been found at depths exceeding fifty fathoms is, 

 according to Mosely," forty-eight. Of these, only five — Caryo- 

 phyllia, Deltocyathus, Plabellum, Bathyactis, and Leptopenus — 

 reach or pass beyond the fifteen hundred fathom line ; the last has 

 thus far been obtained only in water exceeding fifteen hundred 

 fathoms, whereas the other genera range to within fifty or one hun.- 

 dred and fifty fathoms of the surface. By far the greater number 

 of the genera range to within the fifty to one hundred fathom line, 

 and a limited number (Caryophyllia, Paracyathus, Flabellum, Bala- 

 nophyllia, Dendrophyllia, &c.) into still shallower water. Most of 

 the species have a very broad horizontal distribution, and a fair 

 proportion of them approach cosmopolitanism. The range of Ba- 

 thyactis symmetrica, above noted, is practically world-wide, indi- 

 viduals of the species having been obtained from the Azores, the 

 Massachusetts coast, the Bermudas, the east and west coasts of 

 South America, Kerguelen Island, the coast of Australia, the Mo- 

 lucca seas, and the coast of Japan. Scarcely less extensive is the 

 range of Deltocyathus Italicus. Caryophyllia communis has been 

 taken off Nova Scotia, the Azores, the Bermudas, and the Cape of 

 Good Hope. The only genera which appear to be restricted in 

 range are Stephanophyllia and Sphenotrochus, which as yet have 

 been obtained only from the shallow seas of the Malay Archipelago. 

 The compound Madreporaria of the deep-sea are very limited, both 

 specifically and individually, the most abundant form dredged by 

 the " Challenger " being a species of Lophohelia (L. prolifera). 



In their relations with fossil forms the deep-sea corals have re- 

 vealed very little of special importance. Somewhat more than one- 

 third of the genera are represented in the Tertiary formations, and 

 a considerably smaller number (Caryophyllia, Trochocyathus, The- 



