ALCYONARIA WHITELKGGE. 317 



(2.) Smaller deep seated spicules with acute points and a few 

 scattered spines. Size '3 by '05 ; -4 by '05 mm. 



J3.) Curved collar spicules with a few low rounded tubercles 

 rather blunt ends. Size '3 by -03 mm. 



(4.) Operculate spicules with the free end acute and spiny, the 

 lower end blunt. Size '15 by -02 mm. 



(5.) Tentacle spicules slightly curved with a few distant low 

 spines. Size ! by -01. 



The colour of the spicules by transmitted light varies from light 

 to dark red. The stem when dried, appears as if coated with 

 small silvery granules, this effect is produced by the tubercles 

 which are in common with the rest of the spicular surface 

 invested by a hyaline sheath becoming silvery white when dry. 

 Colour in formol is dark purplish-red. 



Muricella purpurea appears to be a very distinct species charac- 

 terised by its gigantic spicules. 



FAMILY PLEXAURID^. 

 PLEXAURA ANTIPATHES, Jasper. 



Gorgonia antipathes, Esper, Die Pflanzenthiere, ii., p. 90, pi. 

 xxiii., fig. 1, 2 ; Kolliker, Icones. Hist., pt. ii., 1866, p. 138, 

 pi. xviii., figs. 21, 22 ; Klunzinger, Die Korallth. de Rothen 

 Meeres, 1877, p. 51, pi. iv., fig. 1. 



There is one large example referred with some little doubt to 

 this species, it appears to be common, numerous specimens being 

 in the Museum collection from the New Hebrides, Fiji, and other 

 coral islands. The colony is 600 mm. in height and 300 mm. in 

 breadth, the main stem is 25 mm. in diameter near the base, at a 

 distance of 80 mm. it divides into two main branches, each of 

 which bears a great number of branchlets, the whole forming a 

 much ramified tree-like colony. Primarily the branching is 

 usually in one plane, but owing to the twisting in and out of the 

 branches during growth, this bilateral feature is somewhat 

 obscured in the adult colony, if however the origin of the branches 

 is carefully noted it at once becomes evident. 



The branches are lateral and alternate, but frequently absent or 

 suppressed on one side, the buds appearing as low elevations ; they 

 are a little compressed in the plane of branching, after attaining 

 to a length of from 5 to 8 mm. they take a sudden bend upwards 

 and the further growth of the shoot is continued in a line more 

 or less parallel to the parent branch. 



The terminal twigs are cylindrical and of equal thickness 

 throughout, or tapering gradually and ending in low conical 

 points, whilst some few are club-shaped with obtusely rounded 

 apices, they measure from 3' to 5- mm. in diameter. 



