ALCYONARIA — J. A. THOMSON AND DORIS L. MACKINNON. 685 



branches. All these ramifications bear numerous twigs which 

 . alternate in a single row along each side. There are about 

 thirteen twigs in each row in a length of 5 cm.; the average 

 length of a twig is 4 cm. 



The polyps occur in a single row on each side of the twigs and 

 branches- -those of one row alternating with those of the other. 

 There is great evenness and regularity in their arrangement ; 

 they never encroach on the middle line. There are about ten 

 polyps to 1 cm. in each row ; the tip of one polyp just reaches to" 

 the base of the one immediately above, the length of a polyp 

 being 1 mm. Among the normal-sized polyps in some of the 

 specimens there are here and there large swollen polyps of about 

 twice the size of the others. These contain reproductive bodies. 



Seen with a lens, the entire surface of the colony, both ccen- 

 «nchyma and polyps, presents a glistening frosted appearance 

 that is very characteristic. The axis is almost black, and bears 

 fine longitudinal striations. 



The polyps are armed with well-defined longitudinal rows of 

 broad, overlapping scales ; there are about six of these in the 

 . abaxials, but in the lateral rows the number is considerably 

 reduced, and the adaxials are indistinct. The operculum of eight 

 isosceles triangles is rather high and conical in the normal-sized 

 polyps, but much lower and flatter in the large individuals. The 

 armature of the two kinds of polyps does not otherwise differ in 

 any marked way, except that the scales on the bodies of the large 

 polyps are much larger than those on the small polyps. 



The polyp scales are rather thin, fan-shaped " ctenoid " forms, 

 with a well-marked nucleus surrounded by tuberculate warts, 

 and a relatively broad clear border round the upper half of the 

 scale, bearing a few strongly-marked radiating ridges. The 

 following measurements were taken of length and breadth in 

 millimetres :— -255 x -204; -204 x -238; -17 x -136. 



The opercular scales are, as usual, isosceles triangles with a 

 median ridge, bearing numerous small warts without definite 

 arrangement. These scales are throughout of very uniform size 

 — '459 X "221 mm. The scales of the coenenchyma are irregularly 

 circular or oval; they are smaller than those of the polyps (*107 

 X 'ISG mm.; '102 x "102 mm.), and have a number of warts 

 surrounding an approximately central nucleus. 



The colour of the colonies is usually light brown ; one dried 

 specimen has a pinkish colour, which is apparently soluble, for a 

 , piece put in alcohol stained the liquid pink after a short time. 



Locality. — Coast between Port Jackson and Port Hackings, 



