TUNICATA. 337 



The ascidiozooids are very small, of a translucent grey colour, rather closely placed, 

 and are mainly in the superficial 2 millims. This colony (fig. 11) was dredged at 

 Station LIV., in the northern part of the Gulf of Manaar ; depth, 10 to 30 fathoms. 



A few other smaller Psammaplidium colonies were found which are too fragmentary 

 or imperfect to describe. Some of these are from Muttuvaratu Paar (Station LIX.), 

 9 fathoms. Others are small sandy lobed masses with areas of black test showing at 

 the ends of the lobes. The test is densely pigmented black, the branchial aperture is 

 eight-lobed, and the atrial has a languet. The masses are about 3 centims. x 1 centim., 

 and the locality is Gulf of Manaar. 



FAMILY: DLDEMNID^E. 



Hypurgon skeati, I. SOLLAS Plate VIII. , fig. 1, and Plate IX., fig. 5. 



This remarkable form was described by Miss I. B. J. SOLLAS from a specimen found 

 at Pulau Bidang in the Malay Peninsula ; and my specimen, from the pearl banks in 

 the Gulf of Manaar, agrees sufficiently closely in detail to be referred not only to the 

 genus but to the same species. 



The single Ceylon colony measures over 8 centims. x 4 centims. between its extremes, 

 but is spread over a slightly branched tube and some tufts of Algse, as seen in 

 Plate IX., fig. 5. The surface is of a warm grey -green colour; and the ascidiozooids, 

 measuring 0'3 millim. across their free ends, are arranged in single lines on each side 

 of the branched cloacal tubes which meander over the surface, with some few occa- 

 sionally scattered between (Plate VIII. , fig. 1) a more regular arrangement than is 

 described by Miss SOLLAS. 



Didemnum areolatum, n. sp. Plate VIII. , figs. 26 and 27. 



Colony encrusting, about 6 centims. x 4 centims. over all, of irregular shape, and 

 2 millims. thick ; with numerous small systems of four, six, or more ascidiozooids 

 (figs. 26), which gives the surface an areolated appearance. 



Ascidiozooids of a dirty white colour, due to the calcareous spicules that surround 

 them, while the test between is an amber brown. The branchial apertures show as 

 conspicuous dark points. Ectodermal processes run out into the test. 



Test much vacuolated in the lower part (fig. 27) and having many small pigment 

 cells in the upper part giving the brownish colour. There are also spherical calcareous 

 spicules which in some places become stellate with blunt rounded points, but in others 

 are merely knobbed (fig. 27). 



Tailed larvae are present in the test (taken March 20). 



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



Leptoclinum margaritiferae, n. sp. Plate VIII. , figs. 19 to 22, and Plate IX., fig. 7. 



The Colony is a large, moderately thick encrusting mass covering a clump of four 

 pearl oysters (Plate IX., fig. 7). The surface is smooth and soft. The colour when 



2 x 



