190G.] ALCYOXARIAKS FROM ZAXZIBAR. 435 



The tentacles were measured in two specimens and were found 

 to vary from 2-95-3 mm. in length. The surface spicules 

 (0-5 X 0-05) are longer than the spicules of any of the other 

 specimens. The axial polyps vary from 57-59 mm. in length 

 and from 1-2-1 -3 mm. in diameter. The average length of the 

 lateral polyps is 4 mm. 



The axial polyp treated with boiling caustic potash showed n 

 firm compact tube marked by longitudinal ridges, and formed of 

 two layers of spicules, an outer layer of stouter spicules, an inner 

 of more slender forms. 



Locality. Wasin, 10 fathoms. 



In another specimen there is a rhizoid-like attachment. The 

 primary axial polyp has been broken, but it is still 67 mm. in 

 length. The complete secondary axial polyps are 95 mm. and 

 72 mm. in length. The lateral polyps are arranged irregularly 

 on the axial polyps. On the lower part of the secondary axials 

 they are 3 mm. by 3 mm., while on the upper part they are 

 2-6-3 mm. by 1*6 mm. 



The axial polyp treated with boiling caustic potash shows a 

 coherent tubular axis formed of two layers of spicules, an outer 

 layer of stouter spicules with more prominent spines and an inner 

 of longer, more slender spicules with few spines. 



Locality. Wasin, 10 fathoms. 



In another specimen the colour was light brown, the lateral 

 polyps were about 3 mm. in length, and the longitudinal grooves 

 were much less marked than in those above described. The 

 spicules are transparent spindles with long, irregular, sometimes 

 branching spines. The following measurements were taken of 

 length and breadth in millims. : — 0-12x0-04; 0-14x0-05; 

 0-18x0-05; 0-2x0-06. 



Locality. Kokotoni Harbour, Zanzibar West, 5 fathoms ; Wasin 

 Channel, 10 fathoms. Previously recorded from Arafura Sea, 

 49 fathoms. 



Family Ccelogorgtid^. 



CcELOGORGiA PALMOSA Wright & Studer. 



A number of fragments which are evidently the portions of a 

 large colony. In some of the larger fragments the axial polyp of 

 the first (?) order attains a diameter of 5 mm. 



The specimen agrees closely with the description given by 

 Wright & Studer, except that in the tentacles, which are short 

 and stumpy, there are four rows of pinnules on the oral surface, 

 and in the outer row there are usually ten pinnules, not eight as 

 stated in the ' Challenger ' Report. The colour of the colony 

 when preserved in spirit is a very pale green, but when dried it 

 is almost white. The green colouring-matter is very soluble in 

 spirit. 



The present specimen also shows a greater degree of elasticity 

 than that ascribed to the 'Challenger' specimen; when dried, 

 however, it is very brittle and hard. 



Proc. Zool. Soc— 1906, Yol. I. No. XXIX. 29 



