166 "THETIS SCIENTIFIC RESULTS. 



the calyx scales ia millimetres : — -544 x -442 ; -408 x -595 ; 

 •289 X -425 ; -272 x -306 ; 204 x -374 ; 357 _x -374. The 

 eight opercular scales are of equal size — 425 x -238 mm.; 

 •391 X -204 01™. They are high, sharply-pointed isosceles 

 triangles, bearing a strong median ridge ; another ridge runs at 

 ri»ht angles to the median ridge across the basal portion, so that 

 the two together form a sort of T-square. Numerous small warts 

 and jagged projections are grouped along the sides of the main 

 ridges, and occur more sparsely over the " blade " of the scale ; 

 the margins of the two long sides of the scale are entire. The 

 spicules of the coenenchyma are for the most part scales, thicker 

 than those of the calyces, and without the clear border ; they 

 show a diversity of form, oval, fan-shaped, triangular, etc., and 

 are closely covered with tuberculate warts which surround an 

 excentric nucleus; their dimensions are: — -374 x 391 ram.; -323 x 

 •153 mm.; 272 x ^204 mm.; 204 x 17 mm. There are also a few 

 small approximately spherical bodies, covered with warts, 068 x 

 •068 mm.; -085 x -085 mm.; -102 x -102 mm. 



The colour of the colonies is light brown with polyps, of a lighter 

 shade. The axis is dark brown to greenish-bronze, and is finely 

 grooved. 



This species agrees in many respects with Plumnrella spinosa, 

 Kiikenthal. P. spinosa, however, has the opercular scales of 

 very unequal .size, and the scales have throughout a rather 

 different type of ornamentation from that in our specimens. 



Locality. — Eleven miles E. by N. of Broken Bay, 30-40 

 fathoms. 



PLUMARELLA CORRUSCANS, sp. nov. 

 (Plate Ixv., fig. 4; pi. Ixviii., lig. 8 ; pi. Ixxvii.) 



Stations 40, 44, 47. 



This is an extremely beautiful and graceful form with typically 

 feather-like blanching. It is well represented both among the 

 dried specimens and among those in spirit. The largest specimen 

 is an almost perfect colony, about 44 cm. high, with a maximum 

 breadtli across the branclied portion of 26 cm. A well-develojied 

 calcareous expansion, altout 2 mm. thick, attaches the colony to 

 the substratum. From this there rises a cylindrical stem, 6 mm. 

 in diameter, which almost from its origin gives off twigs in a 

 single row along each side. At a height of about 19 cm. the stem 

 divides into two main branches, which in their turn give off lesser 



