2 2"? 



there is a close similarity to the branching of such a species as 

 Dasygorgia (Chrysogorgia) flexilis (W. and S.) all the primary 

 branches being given off along a definite line on one side of the 

 axis. This line is, however, not spirally twisted, and the colony 

 is consequently branched in one plane only, and does not form,, 

 therefore, a bushy or shrubby colony, as is usually the case with 

 the branched species of the family. Secondary, tertiary and in 

 some cases quaternary branches are given off from the primary 

 branches. The terminal branches may be 20 mm. in length, but 

 it is characteristic of the species that the axes of the terminal 

 and subterminal branches are very fine and hair-like 0.1-0.02- 

 mm. in diameter. The axis is throughout fibrous and horny, but 

 it contains a considerable quantity of calcium carbonate in the 

 form of fine amorphous granules. 



The coenenchym is missing on the unbranched stem and very 

 thin on the larger branches, but it becomes thicker proportion- 

 ately on the secondary branches, and reaches its greatest relative 

 thickness at the end of the terminal branches. At a distance of 

 2.5 mm. from the extremity of a branch I found that the total 

 diameter of the branch was .15 mm. and of the axis .025 mm. 



The anthocodiae are all partially retracted into long cylindrical 

 calicles i mm. in length. These calicles are set at an acute 

 angle, and are directed towards the terminal extremity of the 

 branch. The calices are very numerous, crowded on all sides' of 

 the terminal branches and closely set on the sub-terminal 

 branches. Both calices and coenenchym are protected by a great 

 number of calcareous overlapping scale-like spicules, arranged in 

 a single layer. 



The characteristic feature of the species is that nearly all 

 these spicules are of the same general shape, i.e., a very thin, flat 

 double disc or double paddle. The size varies from O'l x o"04 

 (greatest breadth or O'Oj breadth across the neck) 

 to o"i5 X •035 ("03 across the neck). A few simple 

 spindles of the shape shown in fig. 13c. may be found,, 

 and these and all other varieties are rare or very rare. The 

 spicules are very nearly smooth, but in some cases a fine pattern 

 and a minute serration of the edges may be seen (fig. 1 3d.). 



The colony is female. Each zooid contains not more than 

 one ripe ovum ; but young zooids and adult with no ova occur on 

 the same branch. (Plate IX., fig. 17.) 



The genus may be characterised as follows : — 



Colony branching in one plane. Axis becoming very thin in 

 the terminal branches. Calices numerous and situated on all 

 sides of the terminal and subterminal branches. Spicules very 

 thin double discs or double paddles, numerous, overlapping, in 

 one layer on calices and coenenchym. 



