156 " THETIS " SCIENTIFIC RESULTS. 



secondary branches which ran parallel to one another. As the.>e 

 secondary branches are nearly as thick as the main branch from 

 which they spring, the eftect of a repeateii dichotomy is produced, 

 an effect that is heightened by the tendency of the main branch 

 to bend outwards after each brancli is given off, so that its course 

 describes a, series of shallow curves. The secondary bianclies 

 rise straight upwards and may remain unbranched throughout 

 their length, or may divide dichotoniously- Branching is strictly 

 in one plane. 



The polyps are arranged in close spirals all over the larger 

 colonies, though one young specimen shows the polyps in a 

 single alternating row on each side of the branch. 



The polyps are club-shaped, with truncated mouths ; they are 

 duected upwards, and bent towards the stem. lu the largest 

 specimen the upper parts of the polyps Imve all been rubbed off, 

 which produces a dece(itive appearance of very short, truncate 

 polyps with their mouths directed outwards from the stem. 



There is a considerable variety in the spicules (PI. l.xvii. fig. 1). 



(1) Tiiere are somewiiat flattened, curved spindles, produced 

 on the conve.x side into a number of sharp, prominent teeth. The 

 following measurements were taken of lengtli and breadth in 

 millimetres. --238 x -102 ; -187 x 085 ; 1 18 x -068 ; -102 x 051. 



(2) .Spicules of similar form to (1), but simpler and with only 

 a few small warts.— 153 x 051 ; 136 x -053 ; 102 x 034 mm. 



(3) Small " Blattkeulen " with a very small shaft, bearing 

 sometimes a few warts, and supporting a group of sharp, blade- 

 like projections.— -102 x -085 ; -09 x -068 ; -051 x -032 mm. 



(4) Small irregular bodies and " capstans." — 085 x "085 ; -102 

 x 0-85 ; 0-68 x Uol mm. 



The colour of the colonies is pale-brown to cream. 

 Previously recorded from the Indian Ocean, and Port Jackson, 

 New South Wales, 35 fathoms. 



MOPSEA ENCRINULA, Lamarck. 



Mopsea eiicrinula, Wriglitnnd Studer, Chall. Bep., Zool., xxxi., 

 1889, pp. 43-44, pi. vii., figs 1, 1% l^, pi. ix., fig 11. 



Stations 34, 44, 47. 



A few incomplete specimens in the present collection agree 

 closely >vith the description of Mopsea eiiorinula (Lamarck), given 

 liy Wiight and Studer. Brauching is pbmie like in one plane ; 

 the club-shaped polyps, 1 mm. long, cover the brarches aid twigs 

 in a close spiral, and are incurved towards the stem. Many of 

 the spicules are yellow and white flattened s|)indles, approaching 

 the " lancet-shaped plates " of Wright and Studer's description. 



