THE ALCYONARIA OF THE MALDIVES. 509 



2. Sarcophi/tum gluucum (PI. XXVIII. figs. 3 and 4), 1833. Quoy et Gaimard (p. 270, 

 PI. XXII. figs. 11 and 12), 1886. Marenzeller (p. 352, Taf. ix. figs. 1 and 2). 



A single well-preserved specimen was taken on the reef of Hulule, Male Atoll. 

 Mr Gardiner observed this species to have large lobes much covered with mucus, with 

 the polyps not generally completely contracted when living, even if exposed to low tide. 



Specimens from different localities vary considerably in .size. This specimen is 22 mm. 

 high, the capitulum is .59 mm. x 45 mm. in diameter, and in the middle is 9 mm. in thickness. 

 The margin is thrown into four large folds. In the middle of the disc the autozooids, which 

 when expanded are about 2 mm. across the crown, are from 3 — 5 mm. apart, but on the 

 margin are younger, smaller and only about 1 mm. ajjart. The siphonozooids are very 

 regularly arranged between the autozooids, and are most numerous in the middle of the 

 capitulum, where there may be from 6 — 13 siphonozooids in a straight line between two 

 autozooids; on the margin there are only from 1 — 3 between two autozooids. The colour 

 of the specimen in spirit is of a greenish stone colour, in the living condition the green 

 colour is more intense. The specimen yields readily to the touch, but is fairly tough in 

 texture. The stalk is short, thick and cylindrical, its surface is smooth and unwrinkled. 



The species has so far been described from Australia, Red Sea, Tonga Island, Viti 

 Island, and now Maldive Islands. 



The autozooids are large, well-marked, and of a deep cream colour in spirit. Many 

 of them are completely retracted. The average surface diameter of an autozooid cavity is 

 1 — 1"5 mm. The tentacles when expanded are long and slender with short simple pinnules 

 in a single row down each side. Small spicules in the form of slender spindles are im- 

 bedded in the walls of the tentacles, and are so arranged that when an autozooid contracts 

 the tentacles come together to form a cone, and the delicate fleshy parts are enclosed in 

 and protected by a conical cap of spicules. The average diameter through the contracted 

 crown of tentacles is 1'4 mm. 



In the preserved condition the stomodaeum is much convoluted ; the siphonoglyph is not 

 readil}' seen, and, indeed, can only be distinguished in stained sections. The eight mesenteries 

 are well-marked and provided with large mesenterial filaments, which are much convoluted 

 at the beginning of their course. Each of the two dorsal mesenterial filaments has a groove 

 running down the middle, lined by ciliated cells. The ventral and lateral mesenteries are 

 rounded in cross section as in Alcyonium. I have observed no generative organs in this 

 specimen, but in a specimen taken by Willey in Blanche Bay tj^ical Alcyonarian ova 

 measuring from 05 — '25 mm. in diameter were seen on the mesenteries. 



The siphonozooids are rounded on their external surface, with the mouth sunk in a 

 slight depression in the middle. Their surface diameter, which appears to be constant, is 

 about '2 mm., and they are usually arranged with the broad diameter of the stomodaeum 

 in a definite direction. Their length varies according to age or to the proximity of an 

 autozooid. When seen in longitudinal section a siphonozooid is conical in shape, the external 

 surface being the base of a cone. The coelenteric cavity is prolonged at its apex into a 

 longitudinal endodermal canal as in the species described by Moseley (1875, PL XIII. fig. 2). 

 The stomodaeum is very short and broad in this form, the average length being 'IG mm., 

 which is only half the length in certain other species (see table, p. 506). It is T-shaped 

 in cross section, the siphonoglyph being well marked. 



