EEPOET ON THE ALC YON ARIA. &1 



attaining a length of about 130 mm., twice dichotomizes. There is a pretty regular series 

 of intervals of 10 '50 mm. between the side twigs ; the diameter of these twigs tapers from 

 1 mm. to the thinness of a hair. The total expanse of the fan-shaped colony is about 

 450 mm. at its widest portion. The axis is brittle. 



When the drawing on PL XII. was made, the remainder of the branches had not been 

 found, but this description is taken from the specimen as complete. 



The ccenenchyma on tlic axis is thin, but covered with a single layer of large, 

 irregular, thickened oblong or triangular scale-like spicules, which are jiroportionaUy 

 denser on the younger portions of the twigs. 



The polyps are in verticils of threes, fours and fives, with the tentacular region looking 

 upwards and inwards towards the stem ; there is an interval of about 3 mm. between the 

 verticils. The polyps are (contracted) about 5 mm. long by 2 mm. wide at the basal 

 portioru At the base of each polyp the large spicules of the axis seem to form a bilateral 

 collar, under cover of which is inserted the fiist large horned annular spicule, which, 

 broadly expanded on the dorsal aspect, completely svuTOunds the lower part of the body 

 of the polyp ; beneath this is a second large annular spicule with many spines, and with 

 the ventral portion, larger than in the former spicule, it is apparently joined by fibre to the 

 former, within which it is movable. These spicules do not present an appearance of being 

 lateral spicules joined together. The opercular spicules are eight in number and form 

 a complete operculum over the tentacles. The six opercular spicules nearest the dorsal 

 aspect of the polyp are larger and more perfect than the two on the inner or ventral 

 aspect ; they are keeled and slightly overlap each other when closed. 



Spicules. — Those of the ccenenchyma are scale-like but various as to shape ; the oblong 

 forms measure 2-0 "5 ; 1-0 '5 ; r5-0'75 mm. Those at the base of the polyps are oblong, 

 curved, forming a collar, and measure 175 by 075 mm. The two-horned annular spicule 

 forming the second row measures from base to extremity of spine 3 mm., with a broad 

 diameter of 1"5 mm. The second annular spicule is 3 mm. (to end of spines) by 175 mm. 

 in the expanded ^^ortion, and 1*50 mm. in the narrowed or neck-like part. The oper- 

 cular spicules of the outer row measure l-O'S; 1 "25-075 ; 1-075 mm., and are triangular 

 in form with broad bases. Of these the outer four seem to fit closely together when the 

 tentacles are withdrawn, they then slightl}^ overlap and lie almost against the main 

 stem or its branches. In shape tliey are not unlike the petals of a Crucifer, the claw 

 broadly expanded, the blade deeply pinched in. Tlie spicules are in general punctate 

 all over. 



This species, originally described from Japan, has been found ofl" Bourbon (Paris 

 Museum, 1862; in this specimen the polyps are very small, 2 mm. by 1 mm.), and is 

 now described from the Southern Pacific (Fiji). 



Habitat. — Station 174c, of Kandavu, Fiji Islands; depth, GIO fathoms; bottom, 

 Coral mud. 



