48 



further characterised by the marked difference in the colour of the polyps on 

 the main stem from that of those on the three large side branches. 



The stalk is short, measuring 3 cm. in length, about one-third of the total 

 height. It is thick and gives oflt' from its base a number of short, thick stolons. 

 It has a granular appearance and a leathery texture ; the ujjper portion is 

 covered by the reflexed lower branches. 



The polyparium is much flattened, of no regular outline, having a ragged 

 appearance owing to the branching arrangement. From the lower part of the 

 stem a number of small branches are given off, from the stem next arise two 

 large cylindrical side branches which stand almost at right angles. After a 

 considerable distance the stem again gives off two side branches in the same 

 plane as the former two ; of these, however, one is larger and more cylindrical in 

 shape, while the other is scarcely distinguishable from the small branches which 

 rise from the whole surface of the stem and side branches. The small branches 

 which arise from the main stem all show a slight flattening, while this is not so 

 marked in the small branches of the main side branches. The lower branches 

 of the stem are flattened, leaf-like structures, two of which practically sur- 

 round the stem in collar-fashion, leaving only two small free spaces between 

 them. Directly below these two open spaces rise two smaller branches with 

 cylindrical bases and flattened upper portions which fill up the gaps between 

 the edges of the two larger leaf -like branches. Directly above the free spaces 

 two small branches with slightly flattened stalks arise. 



The polyps are arranged in bundles of from three to seven individuals each, 

 placed on stalks which diverge to a considerable extent. On the edge and on 

 the upper surfaces of the flattened branches polyps occur singly or in groups. 

 The polyps are small roundish bodies measuring 0'72 mm. in height and 0"66 mm. 

 in breadth. They are placed at an obtuse angle on stalks which measure about 

 1'2 mm. in length, but which in some cases in the lower part of the polyparium 

 may reach a length of 2 mm. The polyp-spicules are arranged in eight double 

 rows each consisting of five to seven pairs of converging spicules. The second 

 uppermost pair may be longer than the rest and project a little beyond the 

 polyp-head. The polyp-spicules are spindles of about 0:30 mm. in length, the 

 projecting spicules averaging about 0'48 mm. and jjrojecting about 015 mm. 

 beyond the polyp. They bear a fair number of simple spines which on the 

 projecting part of the spicule are directed towards the tip. On the aboral 

 surface of the tentacles two rows of flattened irregular toothed spicules lie 

 closely packed together. 



The Stiitzbilndel is well develo})ed, and consists of a number of spicules of 

 which the tips of three or four project beyond the polyp. In most they average 

 about 1'5 mm. in length, but others are 3"2 mm. long and project 0-8 mm. 



Cortical spicules : (a) Those of the stem are spindles either straight or 



