178 THE VOYAGE OF H.M.S. CHALLENGEE. 



interuodes are seen to be white, cylindrical, and deeply and spirally grooved, they are 

 of a stony hardness ; this grooving is partly visible through the coenenchyma. The 

 terminal internodes are horny, yellow, often waved, not very calcareous, but decidedly 

 sclerosforOTC. 



The polyps are placed on the sides of the branches ; they are completely retractile 

 within the coenenchyma, being indeed when completely withdrawn sunk below its level, 

 and thus not presenting the slightest trace of verrucse. The dorsal and front portions of 

 the branches are free from polyps, which sometimes form a single row on the sides of the 

 branches, but occasionally they occur in clusters. 



The coenenchyma is thin and friable, with an outer layer of large short spiny spindles ; 

 the spicules around the polyp openings are long spiny spjindles. 



Colour a dirty yellow, polyp openings pink. 



The spicules measure: — the Stachelkeule 0"18-0'08 at top and 0"02 mm. at bottom 

 of spicule, 0"12-0'04; a few like Blattkeule, but very small, are found, 0"04-0'04 mm. 

 The bent spiny spindles measure 0"2-0"06 ; 0"2-0'02 mm. The double crosses 0"2- 

 0-06 ; 0-06-0-04 ; 0-04-0-04 mm. 



Habitat. — Reefs, Samboangan, Philippines. 



Melitodes nodosa, n. sp. (PI. XL. fig. 10). 



Fragments of several colonies, dredged at Japan and off the New Hebrides, are 

 in the collection ; they appear to be distinct enough to merit description. 



The colony is attached by an ii-regular calcareous basal disc, and may have been about 

 130 mm. in height and from 60 to 80 mm. in diameter. The branches arise all in the 

 one plane; the internodes vary from 5 to 10 mm. in length, the shortest being nearest 

 the base, where the diameter is 2 mm., they are cylindrical and slightly grooved. The 

 nodes are prominent, the larger being 3 "5 mm. high by 2*5 mm. broad. The terminal 

 twigs are slender and not more than 0'5 mm. in diameter. It is noteworthy that some 

 of the branches are given off from the internodes. 



The branches only anastomose very feebly, so as to form but a few very wide meshes. 



The polyps are clustered all over the front portion of the branches ; sometimes even 

 occurring on the nodes, but the back portion of the colony is almost destitute of polyi^s. 

 This arrangement of the polyps is not so well marked on the terminal portions of the 

 branches, where the polyps are to be found all round the axis. The polyps are retractUe, 

 within well-marked verrucse, of from 0"75 to 1 mm. in diameter. 



The general colour of the colony is a reddish-brown ; the nodes being of a darker 

 hue. Deprived of its coenenchyma and polyps, the colour of the axis is a yellowish-red. 

 The polyps are of a yellow colour. 



The spicules of the coenenchyma are irregular curved spindles with long blunt 



