436 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr. 10, 



Local it (J. Station 12. 



Previously recorded from Zanzibar {JRousseau) ; Nossi Be in the 

 Mozambique Channel, 10-12 fathoms {Keller). 



CcELOGORGJA REPENS, sp. n. (Plate XXXI. fig. 1 .) 



Several spreading colonies hardly exceeding 6 mm. in height. 

 There are numerous polyps, in some groups of v\duch it is 

 impossible to distinguish the primary axial polyp from the 

 others. The smallest polyps are mere papill?e 1-5 mm. in height, 

 rising from a basal membrane ; the longest project freely for 

 6-8 mm. An average breadth is about 1 mm. The surface is 

 glistening white, and even to the naked eye appears rough and 

 spicular. It is continuously covered with longitudinally disposed 

 spindles. 



On the upper part of the polyps there are eight longitudinal 

 ridges ending in triangular points, which bend inwards to form a 

 kind of operculum over the inturned tentacles. Each ridge is 

 composed of a double row of spicules, and the components of each 

 row overlap so that there may be three abreast at any one place. 

 In the lower part of the polyp the gi"ooves between the ridges are 

 sometimes prominent and bordered by pairs of spicules from the 

 two adjacent ridges meeting like the letter Y with the point 

 downwards. In other cases the lower part of the polyjD seems to 

 be uniformly covered. 



The short and broad tentacles are completely inturned ; they 

 bear about 6-8 rows of short conical pinnules (13-16 in a row) 

 covering the whole of the oral surface. On the aboral suiface 

 there are numerous minute spicules ari-anged in chevron. The 

 spicules of the general surface are spindles with irregular' spines 

 and warts. The following measurements were taken of length 

 and breadth in milhms. :— 0-75 x O'OS ; 0-7 x 0-05 ; 0-4 x 0-04. 



There can be but little doubt that these specimens represent 

 young stages of colonies Avhich have assumed an encrusting habit. 

 They differ conspicuously from G. jycdmosa not only in the habit 

 of growth, but in being rough and in having much larger spicules. 



Locality. Wasin. 



Section B. Pennatulacea. 



Family Yirgulariid^. 



Yirgularia mirahilis Lamouroux, \^y .pedunculata Kolliker. 

 ,, midticcdycina, sp, n. 



Family P e n N A t u l i d ^. 

 Subfamily Pteroeidin^. 



Pteroeides hrachycaidon Kolliker. 

 5, rigidum, sp. n. 



,, pidchellum, sp. n. 



