REPORT ON THE TTJNICATA. 241 



A second specimen in the collection differs somewhat in its proportions from the one 

 figured (PI. XXXYI. fig. 12) and described above. Its dimensions arc as follows :- 

 length, 2 cm. ; breadth at the posterior end, 3"5 cm. Consequently, in this specimen H i 

 base is even broader than in the other, and exceeds the Length of the body. 



The test in this species is solid, and is in one of the specimens enormously developed, 

 forming a large mass, in which the body of the individual is imbedded. The anteriorly 

 placed apertures are both sessile, and have no visible lobes. 



The branchial sac is strongly contracted and rather crumpled. The stigmata are 

 shorter than, but similar in shape to, those of the other two species (PI. XXXYI. fig. 

 13). The internal longitudinal bars are very fine, and are slightly undulated; they are 

 attached to the summits of very large triangular flaps or connecting ducts, which 1 

 from the wide transverse vessels (PI. XXXYI. figs. 13 and 14). 



The tentacles are simple and filiform, but I was unable, without injuring the single 

 specimen examined, to determine their number, and the condition of the dorsal tubercle. 

 These are points, however, of secondary importance, and the species is, I believe, sufficiently 

 characterised without them. 



The alimentary and genital viscera extend in this species for a considerable distance 

 beyond the branchial sac, so as to form a distinct abdomen, which is almost as large as 

 the thorax, and is connected with it by a narrow pedicle traversed by the oesophagus, the 

 intestine, and the genital ducts. 



Two specimens of Ecteinascidia crassa were found attached to the spicules of a large 

 Hexactinellid sponge, dredged off Ki Island, at Station 192 ; September 26, 1874 ; lat. 

 5° 42' S., long. 132° 25' E. ; depth, 129 fathoms; bottom, mud. 



Ecteinascidia fusca, Herdman (PI. XXXYI. figs. 7-11). 



Ecteinascidia fusca, Herdman, Prelim. Rep., Proc. Roy. Soe. Edin., 1879-80, p. 723. 



External Appearance. — The individuals of this species are united into a colony by 

 a short thick irregular stolon. The shape of each individual is very elongated, some are 

 rudely club-shaped. The anterior end is wide and truncated ; the posterior half is narr< >wer, 

 contorted, and passes down into the stolon. The apertures are nearly terminal, both are 

 placed upon the right side of the extremity ; the branchial is near the middle, and the 

 atrial near the dorsal edge. 



The surface is smooth but uneven, especially at the posterior end, where knobs and 

 processes are usually present. The colour is dark brown. 



Length of the body, 47 cm. ; breadth of the body, 1*5 cm. 



The Testis cartilaginous, stiff, opaque, and thickish, especially in the posterior part. 

 sometimes it is rather thin at the anterior end. Vessels are present. 



The M antle is thin ; the muscular bands are distant, bul well-marked, and are of a 

 reddish-brown colour. The larger bundles run longitudinally. 



