186 THE VOYAGE OF H.M.S. CHALLENGER. 



Pleurocorallium secundum, Dana. 



PleurocoralUum secundum, Dana, Zoophytes, p. 641, pi. Ix. fig. 1. 



„ „ Ridley, in Narr. Chall. Exp., vol. i. p. 692. 



Several dead and variously iacrusted fragments of what may have been this species 

 were taken in the Pacific Ocean. They have been already referred to in the Narrative 

 of the Cruise by Mr. Ridley, but are mentioned here to complete the record. 



The largest specimen belonged to a well-branched colony and measures 228 mm. in 

 height ; with a basal diameter of 22 mm. The branching is irregular but with a tendency 

 to spread in the one plane, the branches are stout, measuring from 10 to 15 mm. in 

 diameter at their junction with the main stem ; they are oval on section. There is no 

 trace of any coenenchyma, the stem and branches are finely striated, but nearly the whole 

 surface is covered over with various forms of Polyzoa, &c. This specimen was obtained 

 off the Ki Islands ; it seems destitute of colour throughout. 



A second specimen from off Prince Edward Island may be referred also to this species, 

 it is a single branch, about 130 mm. in height, and with a basal diameter of 10 mm.; 

 it is a dead fragment, but retains the beautiful pink colour of the central portion of 

 the axis ; the axis is broadly oval, in some places even flattened and channelled. 



A third specimen, which like the first has been already recorded by Mr. Ridley, 

 was obtained at Banda ; it measures 55 mm. in height, with a basal diameter of 10 mm. 



It must be borne in mind, as already mentioned by Mr. Ridley, that owing to the 

 absence of all the soft tissues and free spicules from these specimens, their determination 

 must more or less be a matter of uncertainty ; still the weight of evidence seems in 

 favour of referring them all to Dana's species. 



Habitat. — Banda ; depth, 200 fathoms. 



Station 192, off the Ki Islands; depth, 140 fathoms. 



Station 145a, off Prince Edward Island; depth, 310 fathoms. 



Pleurocorallium johnsoni, Gray. 



Pleurocorallium johnsoni, Gray, Proc. ZooL Soc. Lond., 1860, p. 393. 

 „ „ Ridley, Proc. Zool. Soc. Lond., 1882, p. 223. 



No specimens of this species were found in the collection ; but in the Narrative of the 

 Cruise, we find^ that when about 160 miles south-west of Ferro Island (Station 6) "the 

 dredge was lowered at 10 a.m. on the 18th February 1873 with 2200 fathoms of line, and 

 at 5.30 P.M. it was hauled up, and contained some large branches of an Alcyonarian 

 Coral allied to Corallium. Some of the larger branches were nearly an inch in diameter. 

 The central portion of the axis was very compact and of a pure white colour, while the 

 surface was glossy black. The whole of the Coral was dead, and appeared to have been 



1 Narr. Chall. E.xp., vol. i. pp. 125, 182. 



