682 " THETIS SCIENTIFIC RESULTS. 



Genus PLUMARELLA, Gray. 



PLUMARELLA L^VIS, sp, nov. 



(Plate Ixvi., fig 1 ; pi. Ixviii., fig. 4; pi. Ixxv.) 

 Stations 44, 47, 48. 



A number of incomplete branching pieces, and two complete" 

 colonies, of which the larger is 38 cm. high, with a width of 42: 

 cm. across the branched portion. Branching is strictly confined 

 to one plane. From the main branches lesser branches are given 

 off alternately from each side at rather wide intervals ; these- 

 branches bear long, slender, relatively sparse twigs, alternating 

 in a single row along each side, about five to six on each side in 

 a stretch of 5 cm. These twigs are from 3-7 cm. long, with an 

 average diameter of 1 mm. ; they either fork dichotomously or 

 bear a few scattered twigs. 



The axis is furrowed, and of a dull yellow colour, with a gold 

 sheen in the upper portions of the colony. The coenenchyma is 

 very thin; in the lower part of the colony the furrows or; the 

 axis show plainly through it. One strongly-marked furrow can 

 be traced on both faces of the colony along the median line of" 

 every branch, down to the finest ramifications. 



The polyps alternate in a single row along each side of the 

 twigs and lesser branches. There are ten to twelve on each siile- 

 in a length of 1 cm. They are small, •5-'75 mm. in length, with 

 truncated mouths directed distally. 



The spicules are small, colourless and pale yellow scales of 

 characteristically simple form. The majority are ovals or co 

 shapes, and irregular forms. Their margins are entire or 

 minutely dentate, and their surfaces are either quite smooth, or 

 bear only a few small scattered warts. The following measure- 

 ments were taken of length and breadth in millimetres: — '171 

 x-032 3 -112 X -058; -102 x -038; -077 x -024; -058 x -021.- 

 These spicules interlock or overlap one another slightly ; on the- 

 polyp they are arranged transversely, but the eight longitudinal 

 rows are not very distinct. The operculum is low and flat. 



The colour of the colony is dull yellow to golden-brown. 



Position — In certain respects this species comes very near 

 Plumarellapenna (Lamarck), as described by Yersluys*.- 

 The polyps are very similar, and the spicules have a strong 

 i-esemblance. But, on the whole, the spicules of our specimen 



8 Versluys — Die Gorgoniden der Siboga Expedition, ii. Die Primnoidsej.,. 

 1906, p. 18. 



