338 CEYLON PEARL OYSTER REPORT. 



alive was greyish, mottled and streaked with black and white ; now, after preservation, 

 it is of a pale pink or crushed-strawberry tint. The size of the mass of oysters and 

 Ascidian together is 9 centims. x 7 centims. x 6 centims. over all. 



o 



The Ascidiozooids are numerous all over the surface of the colony, and are usually 

 scattered irregularly. In some places they are in double rows, or there are vacant 

 tracts between them (see fig. 7). Common cloacal apertures are few and small. The 

 anterior ends of the ascidiozooids are about 0'5 millim. across. 



The Test is soft and not opaque. It is of a greyish colour with a slightly pink tint. 

 The calcareous spicules are stellate (fig. 20), but are not very abundant. A thin layer 

 is found on the surface, and in deeper sections they occupy the lines of test which 

 separate the ascidiozooids (fig. 19). There is also a clump of spicules on each side of 

 the thorax of the ascidiozooid. Rounded masses of pigment granules are also present 

 in abundance in the test (fig. 20), as well as small branched test-cells. 



The Branchial Sac has four rows of short rounded stigmata (fig. 22). 



The Tentacles are short and thick, 16 in number. 



The Testis is lobed, with the usual spiral vas deferens (fig. 21). 



Locality: Station XIX. > Palk Bay, south of Mandativu, trawl. 5 fathoms. 



Leptoclinum pantherinum, SLUITER. 



One colony measuring 12 centims. x 6 centims. and several smaller fragments, 

 obtained from Talaivillu Paar at a depth of 8 fathoms, appear to belong to this species. 

 They are of a dirty cream colour streaked with brown. The colour is due to 

 aggregations of pigment corpuscles in the test. There were fully developed tailed 

 larvse in the colony when collected (April 1). Another small colony was dredged at 

 Station LXIX., Chilaw Paar, 8 to 11 fathoms. 



Leptoclinum ceylonicum, n. sp. Plate VII I., figs. 15 to 18 ; Plate IX., figs. 1, 2. 



A number of colonies, large and small, of a white Leptoclinum, which occurs 

 growing over the coarse sand and calcareous fragments of the sea-bottom both in the 

 Gulf of Manaar and in the lagoon at Galle, are so similar in their general characters 

 that, although they show some variation, I think it right to unite them as one 

 species. Two somewhat divergent colonies are reproduced about half natural size, 

 from photographs, in figs. 1 and 2 on Plate IX. Fig. 1 is a colony measuring 

 16 centims. x 15 centims. x 8 centims., from Station XIX., in Palk Bay, 8 fathoms; 

 while fig. 2 is a mass of about 12 centims. x 10*5 centims. x 6 centims., of plano- 

 convex form, from Station II., off Chilaw, 14 fathoms (the flat surface is shown). In 

 each case those figured are samples of several other colonies, and they show well the 

 characteristics of the species. Colonies were also obtained from the coral reef at 

 Galle and from Aripu reef in the Gulf of Manaar. 



The included coarse sand-grains and shell fragments are readily seen, especially in 

 tig. 1, and the interior of the mass contains others which render the substance very 



