522 MR. E. W. SHANN OJ^ 



The polyps arise sporadically from all parts of the colony. 

 They ai'e closely aggregated on the lateral lobes, and are most 

 scarce on the basal portion of the primary lobes. The anthocodise 

 are supported by a " Stiitzbiindel '' (fig. 14), three horny spindles 

 of which project •2--4 mm. beyond the polyp-head. The polyp- 

 heads make an acute angle with their stalks ; the stalk is 1*2 mm. 

 high, the head is 1 mm. in length and 'T-'SS mm. in maximiim 

 breadth. The polyps contain thorny spindles of various sizes 

 and a few clubs. These are sometimes placed horizontally, but 

 are more usually oblique, and in the distal area are ari'anged 

 en chevron. These spindles measure -45 x "035, -^T X '04, -2 x 

 •025 mm. Among the above and extending into the tentacles 

 are numerous little spicules which are nearly rectangular in 

 outline; they measure -110 x '036, '095 x '015, -050 x "015 mm. 

 The " Stiitzibundel " is composed of a number of thorny spindles 

 of a bright yellow oolovir (they resemble at first sight crystals of 

 sulphur). These spicules are ten in number round the base of 

 the polyp-stalk, but there are only three at the distal end. The 

 four spicules which underlie the point of origin of the polyp- 

 head are semi-lunar in shape, the concave sides facing the 

 polyp-head. The " Stiitzbiindel" spicules reach 1*8 mm, in length 

 and •12 mm. in breadth. The cortex of the colony derives its 

 characteristic colour from the enormous number of slim yellow 

 spicules which it harbours. There are also thorny spindles ; they 

 lie pai-allel to and very near the sui>face, and vary very much in 

 size and shape. Some are twice, others only half, the size of the 

 " Stiitzbiindel" spicules. Few ai^e straight, most are semi-lunar 

 or S-shaped, and veiy exceptionally a triradiate form occurs. 

 The ends of the spindles are usually bluntly pointed, but 

 occasionally forms were observed with their ends frayed out into 

 a number of points. The largest measure 3'0 x "28, 2*7 X '30, 

 2'1 X -15, the smallest -67 x '07, -67 x '04, -55 x '05 mm., but every 

 conceivable intermediate stage can be found, A remai-kable 

 feature of this species is the entire absence of spicules from the 

 canal-walls. 



The colour of the colony in alcohol is pale yellow, the polyps 

 are cream -coloui-ed. 



The specimen was taken in Imbiab Bay, where it was left 

 exposed at the lowest tides. 



Two other specimens taken in the littoral region at Tehik Ayer 

 have also been assigned to this species. At first sight they do 

 not resemble closely the type specimen, for they are shorter, 

 broader in proportion, and more bushy in appearance than the 

 colony described above. One of these colonies is 4*3 cm. in 

 height, its base is "8 cm., and the maximum diameter of the 

 capitulum is 3"1 cm. ; the measurements of the other, taken in 

 the above order, are 3 x '7 cm. : 4*5 cm. The apparent difference 

 in the branching from that of the type is due to the fact that 

 the secondary branches are no larger than the lateral lobes, and 

 that both these kinds of offshoot are relatively numerous. The 

 polyps are arranged much more densely than in the type, 



