THOMSON AND EUSSELL— AXIFEEA, 155 



31. Acis spinosa, Thomson and Henderson. 

 Por description see : — 



Thomson and Henderson : Alcyonaria o£ the Indian Ocean^ pt. i. 1906, pp. 77-78, pi. 5. fig. 11. 



A large grey colony branched in one plane and measuring 20 cm. in height by 15 cm. 

 in breadth, seems to belong to this species. A. spinosa is to be distinguished from 

 A. indica, Thomson and Henderson, which it resembles closely, by the smoother 

 ccenenchyma spicules and the longer spines of the verruca spicules. A smaller colony, 

 10X10 cm., was also found. 



Locality. Salomon, 60-120 fms. 



Previously recorded from the Andamans, 45-270 fms. {Thomson and Henderson, 1906). 



32. Acis alba, Thomson and Henderson. 

 Por description see : — 



Thomson and Henderson : Ceylon Pearl Oyster Report, No. xx. 1905, p. 299, pi. 3. fig. 9, pi. 5. fig. 4. 

 Locality. Providence (D 4), 50-78 fms. 

 Previously recorded from Trincomalee and Galle {Thomson and Henderson, 1905). 



33. Acis dejecta, sp. n. (Plate 6. figs. 2, 2«, 4«, 4 5.) 



A very distinctive new species is represented by a number of colonies of a grey-white 

 colour which branch in a more or less horizontal plane, occasionally rising to about 45". 

 The verrucas are exclusively on the sides and under surface of the bi-anches. Another 

 distinctive feature is the large size and scale-like appearance of the superfi.cial spicules 

 of the ccenenchyma. It is the most striking species of Acis that we have seen. 



The colonies rise to a height of l'5-5 cm., and expand on all sides with a diameter of 

 about 7 cm. There is an extremely short common trunk of about 5 mm. in height. The 

 branches are about 3 mm. thick. The axis is horny and flexible. 



The verrucse are somewhat irregularly disposed, but there is a tendency towards 

 arrangement in two lateral lines with a few scattered in the middle. They are separated 

 from one another by intervals of 1-5-2 mm., and there are usually about ten to a 

 centimetre. In many cases a single scale-like spicule stretches from one polyp to 

 another. 



The verrucas appear like small rounded scale-covered buds, about 2 mm. in breadth 

 and 1 mm. in height. The spicules that surround them are imbricating scales. The 

 polyps are very dark in colour. There is an operculum, which is hidden from sight by 

 the scales of the verruca ; it is formed by eight triangles, each composed of two strong 

 curved spindles lying along the base of a tentacle. Numerous large ova are to be seen 

 in the polyps. 



The ccenenchyma contains so many lai'ge plate-like spicules that it is reduced to 

 very scanty proportions. The superficial spicules form a layer of closely-fitted large and 

 thick scales, 3-4-5 mm. long, 1-5-2-5 mm. broad, and up to 1 mm. thick. Below this layer 

 there lies, at least on the larger branches, a layer of sm-aUer, slightly imbricating scales, 



SECOND SERIES. — ZOOLOGY, VOL. XIII. 21 



