CHAP. III.] BAHIA TO THE CAPE. 133 



rated, with a small convex umbilicus in the centre. The costse, 

 which correspond with tlie septa, are distinct to the centre, finely 

 spinous and granulated, subecpial, the primaries and seconda- 

 ries slightly the larger. The septa are subequal, spinous, the 

 larger slightly lobed ; in six regular systems and four complete 

 cycles. The septa of the fourth cycle are connected l)y their 

 inner edge with those of the third, and the latter with those of 

 the second ; the points of connection are sometimes expanded 

 into a plate ; the primary septa reach the centre without any 

 connection. The columella is rudimentary, sometimes covered 

 with a calcilied membranous expansion through wdiich some of 

 the spines project. The synapticula are large, and correspond 

 to one another in the contiguous chambers so as to form four 

 to six more or less regular concentric circles. 



Tills species has been proved by our dredgings to be one of 

 the most constantly recurring of deep-sea animals, with a world- 

 wide distribution. It has been dredged by us fifteen times; it 

 occurred in the !North and South Atlantic, near the ice-barrier 

 in the Southern Sea, off the West Indies, in the North and 

 South Pacific Oceans, and among the Moluccas. It has a more 

 extended range in depth than almost any other animal, having 

 been obtained by us in 30 fathoms off Bermudas, and at all in- 

 termediate depths down to 2900 fathoms. Specimens from 

 2900 fathoms w^ere obtained \\\t\\ the soft parts preserved ; and 

 specimens from 2300 fathoms, of wdiich thirty or more were 

 ol)tained at one haul, were full of ripe ova. Fungia symmet- 

 rica is the only coral which has yet been obtained from a 

 depth greater than 1600 fathoms; it occurs on all kinds of 

 bottoms — on globigerina ooze in the Atlantic, among growing- 

 branched corals {Madracis asperula) off Bermudas, on a bot- 

 tom composed almost entirely of the frustules of diatoms in 

 the Southern Sea, and on red clay with manganese nodnles in 

 the North Pacific. It sustains a range of temperature from 1° 

 to 20° C. 



