ALCYONARIANS. BRIGGS. 81 



Genus PLUMARELLA, f '/>///. 



PLUMARELLA THETIS, Thomson and Mackinnon. 



(Plate ix.). 



Plumarella thctis, Thomson and Mackinnon, Mem. Austr. 

 Mus., iv., 13, 1911, p. 683, pi. Ixvi., fig. 5, pi. Ixviii., 

 fig. 6, pi. Ixxvi. 



Two frond-like branches correspond with Thomson and 

 Mackinnon's description of Plumarella thetis. They are re- 

 markably robust, the larger being 32-5 cm. long, with a 

 diameter of 4 mm. near the base. The branches give off 

 along each side a row of alternating twigs, which remain 

 simple. The twigs are 11 cm. long, with a diameter of 2 mm. 

 There are seven to eight twigs in each row in a length of 5 cm. 



The second frond is 26 cm. long, and has a diameter of 

 3 mm. near the base. The twigs are 7-5 cm. in length, with 

 a diameter of 2 mm. 



The polyps are arranged in close-wound spirals round the 

 twigs, but are scattered irregularly over the whole surface 

 of the branches. They are armed with longitudinal rows of 

 large overlapping scales, of which there are about six in the 

 abaxials ; they are broad, shield-like, and fan-like scales, 

 with a nucleus surrounded by numerous finely-tuberculate 

 warts, and with a clear border between the outer margin and 

 the warted portion bearing radiating ridges -612 x -367mm. ; 

 595 x -280 mm. ; -507 x -367 mm. ; -455 x -297 mm. The 

 opercular scales are isosceles triangles with a strong T-square 

 ridge -472 x -210 mm. ; -455 x -192 mm. The scales of the 

 ccenenchyma are triangular, oval, and fan-shaped, with 

 tuberculate warts surrounding an excentric nucleus -385 x 

 350 mm. ; -367 x -236 mm. ; -280 x -227 mm. 



The colour of the specimens is light-brown. The axis is 

 almost black and bears fine longitudinal striations. 



Locality. Fifteen miles X. 35 E. of Saddle Hill, New 

 South Wales, 34-35 fathoms. 



Distribution. Hitherto known only from specimens ob- 

 tained by the " Thetis " off the coast of New South Wales at 

 the following localities : Eleven miles E. by N. of Broken 

 Bay, 30-40 fathoms ; Station 34, off Port Jackson, 39-36 

 fathoms ; Station 40, off Wata Mooli, 52 fathoms ; Station 

 42, off Wata Mooli, 70-78 fathoms ; Station 47, off Bulgo, 

 63-57 fathoms ; Station 48, off Wollongong, 55-56 fathoms ; 

 Station 53, off Crookhaven "River, 23 fathoms (Thomson and 

 Mackinnon). 



