172 



Melitodes philippinensis, Wright and Studer. 



Plate V. figs. 2 and 4 ; Plate IX. fig. 12. 



A beautifully coloured colony 110 mm. high and 30 mm. in breadth, 

 branching in one plane and anastomosing to form an open network. The 

 branching near the base is irregular, in the upper part of the colony it becomes 

 more decidedly dichotomous. Anastomosis is frequent and takes place in every 

 conceivable manner. The majority of the branches are sinuous but many are 

 almost horizontal, thus joining with the adjacent branch by the shortest 

 route, and giving great inequality in the lengths of the two arms of the 

 dichotomy. 



The diameter of the stem is 2*5 mm. at the base, diminishing gradually to 

 1 mm. in the higher branches. The axis is rough and almost cylindrical. It 

 is bright red in colour and is penetrated by numerous solenia. The internodes 

 vary in length from 3 mm. to 8 mm., but there is no distinct gradation from 

 one part of the colony to the other, the length apparently varying with the anas- 

 tomosis. The nodes are feebly calcareous and brown in colour. They are 

 almost spherical, forming large swellings, especially in the lower portion of the 

 colony where they measure 3"5 mm. in diameter. In the smaller twigs lo mm. 

 is a common measurement. 



The coenenchyma is thin and densely packed with spicules which present 

 a glistening arenaceous surface. It is of a golden-yellow colour. 



The polyps are irregularly disposed, confined to about four-fifths of the 

 surface, leaving a bare space on the dorsal aspect. There is also a hint of a line 

 on the ventral surface. On the nodes polyps are very scarce. They are of a 

 bright coral-red colour and are so thickly set that they give a decided red tinge 

 to the whole colony, in fact the colour of the coenenchyma can only be distinctly 

 seen on the dorsal surface. 



The verrucse measure about 0'75 mm. in height and the same in diameter. 

 They are dome-shaped but their prominence is due in great part to the contrast 

 in colour with the general coenenchyma. On the outer surface eight ridges of 

 spicules are seen and these terminate in lobes which meet over the retracted 

 anthocodife. 



The anthocodiaj are completely retractile. On the base of the tentacles 

 there are four or five pairs of red spicules pointing to the distal end and enclos- 

 ing large angles. Beyond this the spicules are arranged almost longitudinally 

 and are slightly longer. On the pinnules the spicules are colourless and appear 

 white. 



The .spicules of the coenenc^hyma are pale yellow, and present the following 

 types and measurements in millimetres : — 



