290 CEYLON PEARL OYSTER REPORT. . 



is brownish -yellow in older, yellow in younger portions, and is chambered. The 

 spicules are long slender spindles, with few warts, and tri- and quadri-radiate stars. 

 Among the spicules a considerable number are seen with an abrupt bend and one arm 

 long in comparison to the other (golf-club-like). In these there is a poor development 

 of the warts, the long shaft being free from the warty protuberances for a considerable 

 portion of its length, while the short head has a good number of rough warts. 



The spicules measure, length by breadth, in millimetres : 



Projecting opercular spicules, 0*4 X 0-05 ; 0-45 X 0"04 ; 0'4 X 0'045. 



Ordinary spindles, 0"5 X 0'036 ; 0"3 X 0"04 ; 0-6 X 0'045. 



Quadri-radiate forms, - 25 X 0'15 ; 0"25 X 0'02; arms about 0'1 millim. in length. 



Tri-radiate forms, 0'3 X 0'25 ; the arms being about - 12 millim. in length. Some 

 apparently sex-radiate and quinque-radiate forms occur. 



Locality : Trincomalee. 



Acanthogorgia muricata, Verrill, var. indica, n. Plate IV., fig. 11. 



As a variety under this species we rank a beautiful complete colony, which has a 

 height of 78 millims. and a maximum width of 105 millims. 



The basal attachment is a flat spreading portion from which the main stem rises. 



The axis is dark brown in colour, fading to a light yellow in the younger part. It 

 is covered with close set furrows at the base, and at that point has a diameter of 

 3 millims., but it becomes extremely thin at the ends of the branches. The branching 

 is very profuse and is confined to one plane, but the type of branching gives the main 

 stem a slightly zig-zag arrangement. 



The calyces are densely crowded all round the stem and branches. They measure 

 from 2 "5 millims. to 3 minims, in heiffht and have a basal diameter of 0"9 millim. 

 and a width of 1"1 millims. to 1'2 millims. at the crown. At the free end of the 

 calyces there are 8 projecting spicules. The ccenenchyma on the stem and branches 

 is very thin. 



The specimen comes near Acanthogorgia spinosa, but differs from it in having only 

 8 single projecting spicules, while A. spinosa has 8 groups of 2 or 3. The spicules 

 also differ slightly. It agrees closely with A. muricata except for slight differences 

 in the polyps and spicules. The species A. muricata illustrates wide distribution ; it 

 has been previously recorded from Barbados and Funafuti. See Hiles (1899), p. 48. 



Locality : Trincomalee. 



Acanthogorgia ceylonensis, n. sp. Plate IV., fig. G ; Plate V., fig. 12. 



This species is represented by one specimen which measures 55 millims. in maximum 

 height and 30 millims. in maximum width. The branching is both alternate and 

 opposite and is confined to one plane. The polyps are arranged in threes or in twos 

 or in loose spirals. The verrucse vary in height from 0'G millim. to 07 millim. and 

 are placed at intervals of about 1 millim. The spicules are arranged on the verrucas 



