56 THE AUSTRALIAN MUSEUM. 



Branchial, sac with 7 strongly-marked folds on each side. The main 

 vessels, both transverse and longitudinal, very wide. The finer inter- 

 stigmatic vessels much as usual. Stigmata curved and arranged in 

 infundibula. 



Tentacles, 8 very large and much-branched, alternating with 8 very 

 much smaller ones. 



Dorsal tubercle cordate, with the opening anterior, and both horns 

 turned equally outward, but not coiled. 



The specimen described above is one labelled "from Sydney," with 

 no date or other particulars which I happened to have in my possession, 

 and which I thought had better be treated as belonging to this collection 

 of Australian Tunicata. The most notable external characters are the 

 very flat condition of the body and the softness and looseness of the test 

 (PI. Mol. I., fig. 5). No lobes are visible round the apertures externally, 

 but when the test is removed there are rather long well-marked siphons 

 (figs. 6 and 7). The mantle and the alimentary and reproductive viscera 

 are of the ordinary Molgulid character. The most noteworthy point 

 about the branchial sac is the exceptional width of the vessels (fig. 8). 

 A large parasitic Copepod was found in the branchial sac. 



Molgula Forbesi, Herdm. 



Three small specimens attached to the large Ascidia phallusioides 

 and Microcosmus Draschii, from Port Jackson, seern to belong to this 

 "Challenger" species. They are shown on PI. Cyn. IV., fig. 1. The 

 specimen obtained at Port Jackson by the " Challenger " was apparently 

 free, while the present specimens are attached, but in all other respects 

 and details of internal structure they agree with the original description 

 of Molgula Forbesi.* 



Molgula recumbens, n. sp., PL Cyn. VI., figs. 9 13. 



External appearance. Shape ovate, compressed laterally, and attached 

 by the greater part of the right side. Apertures conspicuous, both on 

 long, permanent siphons, which are recurved, so that the branchial 

 points ventrally and the atrial dorsally. Surface even, but entirely 

 encrusted with fine sand. Colour dark grey brown. Length l - 8 cm., 

 breadth l - 5 c.m., thickness '8 cm. 



Test thin, but strong, flexible. 



* "Challenger" Report, Tunicata, Part I., p. 78, 1882. 



