75 



branches have developed more strongly. Above this the stem ends in two 

 blunt conical processes, from the side of one of which a large branch is given 

 otf, the largest in the colony, which almost immediately divides into two. On 

 the tip of this conical process there is a faint indication of polyps, while on 

 the tip of the other there is the beginning of a small branch consisting of a 

 cluster of polyps. All the branches are cylindrical in shape, and give rise 

 directly or by repeated division to the polyp-bearing twigs. The stem itself is 

 slightly flattened in the same plane in which a slight flattening of the poly- 

 parium is found. 



The polyps are arranged in groups of two to ten, and are placed at an 

 obtuse angle on stalks (about 1 mm. long) which diverge considerably. They are 

 oval in shape and average about 0[A mm. in height and 0'(36 mm. in width. 

 The polyp-spicules are arranged in eight double rows ; in the dorsal rows there 

 are four to six pairs of converging spicules, in the others five to seven pairs. 

 In every row one of the uppermost pair is slightly longer than its neighbour 

 and projects a very little beyond the polyp. The lower polyp-spicules average 

 about 02 mm. in length, the upper often measure 0"3(i mm. and project for a 

 distance of 012 mm. They are all covered with numerous small spines. On 

 the aboral surface of each tentacle there are two compact rows of small flat- 

 tened, toothed spicules. 



The Stiitzbundel is well developed, containing a few large spindles of which 

 one may reach a length of 36 mm. and project 1"5 mm. beyond the polyp. 

 The tip of a second spicule may also project a little beyond the polyp. 



Cortical spicules : [a] In the stem there are long slender spindles either 

 straight or curved and bearing numerous regularly arranged blunt spines or 

 roughish warts, and in addition a number of smaller spicules slightly flattened 

 and bearing few simple spines, or with toothed edges. The larger vary from 

 042 to 30 mm. in length and from 0'06 to 0'17 mm. in breadth. The smaller 

 average about 0-12 mm. in length. They are arranged irregularly on the main 

 stem and bi'anches, but more longitudinally on the smaller branches and twigs. 



{/)) In the stalk there are spindles, three- and four-rayed forms, clubs, 

 indigent three- and four-rayed forms, and numerous irregular branched forms. 

 These are all covered more or less thickly with large prominent rough or 

 branched warts, and the spindles often show a very deep bifurcation at one 

 end. In addition there are a few irregular spindles, bluntly dumb-bell-shaped, 

 or tapering forms with a few whorls of warts. 



The spindles measure up to 1 -56 mm. in length and 012 mm. in breadth, 

 while a few of the largest three-rayed forms average about 1"2 mm. in greatest 

 length. 



Canal-wall spicules : (a) In the stem there are small pointed spindles 

 with fairly numerous Ijlunt spines, and a few four-rayed forms, but the majority 



