ALCYONARIA — J. A. THOMSON AND DORIS L. MACKINNON. 687 



^Ineats were taken : — ■323 x -357 ram.; •272 x "255 mm.; '119 x 

 •085 mm. The colour of the majority of the colonies is red- 

 brown; one small specimen is cream-coloured, with very opaque 

 spicules. The axis is greenish-bronze, with fine longitudinal 

 striations. 



Locality. — South Coast, New South Wales. 



PLUMARELLA YERSLUYSI, sp. nov. 



(Plate Ixvi., fig. 4 ; pi. Ixviii,, fig. 2 ; pi. Ixxix.) 

 Station 53. 



The largest specimen has a height of 22*5 cm. with a width of 

 about 12 cm. across the branched portion; the basal attachment 

 is lacking. The branching is confined to one plane, and is 

 typically feather-like. Along each side of the stem and main 

 branches there is a row of twigs alternating with those of the 

 opposite side. The average length of a twig is 2 cm. with a 

 diameter of 2 mm.; there are about fourteen twigs on each side of a 

 branch in a length of 5 cm. The polyps are arranged bilaterally 

 on the larger branches ; on the twigs their arrangement is also 

 lateral, but a few may encroach on the middle line. Usually 

 they stand in a single row, but occasionally the row is doubled. 



The polyps are of two sizes ; the majority are very small, 

 •75 mm. in length ; here and there occur larger, more swollen 

 polyps, 1'25 mm. in length. In the smaller polyps the armature 

 consists of overlapping scales, of which there are about four in the 

 abaxial longitudinal rows ; the lateral rows are very indistinct, 

 and the adaxials practically obsolete ; the uppermost of each 

 longitudinal row is larger than the rest and projects, so that a 

 slight circumoperculum is formed. The operculum is well-defined 

 and conical, formed of eight approximately equal isosceles 

 triangles. The armature of the larger polyps is of the same 

 general type as that just described ; but the longitudinal rows are 

 even less distinct, the polyp scales are rather larger and more 

 numerous, and the operculum is low. 



The polyp-scales are broad and fan-shaped, with a distinct 

 nucleus, numerous tuberculate warts, and a clear fluted margin 

 round the part of the scale that projects when on the polyp. The 

 general appearance of the scales is very similar to those of 

 Plumarella filicoides, but they are markedly thinner, and less 

 heavily sculptured than in that species. The following measure- 

 ments were taken of length and breadth in millimetres : — 

 -425 X -289; -306 x -306; -255 x -187. The opercular scales 

 are similar to those of P.filicoides, but are less strongly ridged — 

 -34 X •204 mm.; -289 x •187 mm. 



