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



The axis is hard, calcareous, brittle, of a whitish-yellow colour, but towards the end 

 of the twigs it becomes more flexible. 



The spicules of the calyx are arranged in four longitudinal rows of seven or eight 

 scales, of which the two dorsal rows contain the largest scales, and on the dorsal aspect 

 are alone visible ; the ventral side of the calyx is scaleless, only on its upper edge is one 

 scale developed as a support for the ventral opercular scales. 



The spicules are broader than high, relatively thin; the prominences radiating from the 

 nucleus to the dorsal edge are not much developed, and become pointed only in the dorsal 

 rows so as to form a row of teeth on the edge. Ribs are weakly developed and only in 

 the uppermost row. Length to breadth in mm. — 0*2-0 "35 ; 0'18-0"35; 0"15-0'25 ; 

 0'13-0"27 ; 0'13-0'23. The ventral scale is triangular, covered with small prominences, 

 0-16 to 0-14 mm. 



The bilaterally arranged opercular scales exhibit a median keel, which ends in a little 

 spine. The dorsal measure 0-3-0-167 ; lateral 0-3-0-17 ; ventral 0-23-0'15 mm. 



The scales of the coenenchyma are tubereulated, thick, bent or oval plates, whose edges 

 are toothed, they lie close together, with the edges touching. Those of the upper layer 

 exhibit the following sizes in mm. Length to breadth — 0-32-0-14 ; 0-4-0-27 ; 0-3-0-17 ; 

 0-35-0-12 ; 0-2-0-06. Lower layer, O'l-O-QS. 



Habitat. — Station 192, off the Ki Islands, south of Papua; depth, 140 fathoms; 

 bottom, blue mud. Only one specimen of this very elegant form was dredged. 



[2. Caligorgia ventilabrum, Studer. 



Cdlligorgia ventilabrum, Studer, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1878, p. 647, 



Taf. ii. fig. 12, a, h, c, d. 



North of New Zealand ; depth, 90 fathoms. 



3. Caligorgia gracilis (Milne-Edwards). 



Primnoa gracilis, M.-Edw., Hist. Nat. des CoraUiaires, t. i. p. 141. 



West Indies, 



4, Caligorgia verticillata (Pallas). 



Gorgonia verticillata, Pall., Elench. Zooph., p. 177. 



,, verticillaris, Solander and Ellis, Zooph., p. 83. 

 Muricea verticillaris, Dana, Amer. Explor. Exped. Zooph., p. 675. 

 Primnoa verticillaris, M.-Edw., Hist. Nat. des CoraUiaires, t. i. p. 140. 



„ „ Kent, Monthly Micr. Journ., February 1870, pi. xlL figs. 8, 9 (figures of 



spicules). 



„ ,, Kblliker, Icon. Histiol., Taf. xvii. fig. 12 (spicules). 



„ „ V. Koch, Mitth. ZooL Stat. Neapel, Bd. iii. p. 546. 



„ ,, V. Koch, Morph. Jahrb., Bd. iv. p. 457, 1878. 



Mediterranean, Azores.] 



