XlCTONARIA — J. A. THOMSON AND DORIS L. MACKINNON. 155 



In tlie lower part of the stem tlie calcareous and Iiornj' joints 

 have approximately equal lengths of about 2 5 mm. ; hut higher 

 up the internodes greatly ])redominate, 3-4 mm., while the nodes 

 are reduced to mere constrictions, -5 mm. in length. The intpr- 

 nodes are white, and bear .somewhat distant longitudinal grooves. 



On the younger colonies and smaller branches the arrangement 

 of the polyps is bilateral, but on the larger branches they may 

 occur all round. In one specimen where they were less obscured 

 by sponge-growth than elsewhere, the jiolyps had a height of 75 

 mm. with a diameter of 1 mm. : they projected from the branch 

 as low, rounded warts. 



The spicules are exactly like those described by Wright and 

 Studer — i.e., massive warty spindles, some almost as broad as 

 long, and approaching splieres. The warts are high and prom 

 inent and finely sculptured. The following measunniients were 

 taken of length and breadth in millimetres. — -261 x 17 ; -25 x 

 •1 ; -2 X 16; 17 x -1. 



This species is distinguished fiom Parisis /'riUicosa, Verrill — (1) 

 by tlie_branches coining oil' at angles of 45^ 60", instead of at 

 approximately right angles ; (2) by the polyps occurring all 

 round the branches instead of being strictly bilateral ; (3) by 

 the smaller size, and greater slenderness of the spicules. 



Locality. — South Coast, New South Wales. 



Previously recorded from Station 163 B, off Port Jackson, 

 35 fathoms. 



Order IV. AXIY^IX, G. von Koch. 



Family 1 SI DAE. 



Genus M O P S E A, Lamouroux. 



MOPSEA DICHOTOMA, FAnnl 



(Plate Ixvii. tig. 1.) 



Morpsea dichotoma, Wright and Studer, Cliall, Hep., Zool., xxxi., 

 1889, pp. 41-42, pi. ix., Hg. 10. 



Stations 48, 47. 53. 



The largest specimen is an almost complete lyre-shaped colony, 

 rising from a slightly encrusting calcareous base to a iieighl of 

 22-5 cm. The main stem, 3 mm. in diameter near the base, 

 divides to form two equal branclii s at a height of 2-5 cm. These 

 two main branches give rise along one side to a number of 



