100 PROFESSOR W. A. HERDMAN ON THE 



material is from Port William, Station 349, Falkland Islands, February G to 8, 1903, 

 6 fathoms. The large colony measures about 14 cm. by 3 cm., and is attached along 

 the length of a Laminaria-like Alga. The test is dark greyish brown, and the small 

 yellow Ascidiozooids show all over the surface as closely placed dots or streaks of a 

 lighter colour. In further details this specimen agrees well with the description of the 

 Australian one. One zooid was, however, noticed with an eight-lobed branchial aperture. 

 The stomach has longitudinal folds. The stigmata are large. The dark colour of the 

 test is due to dense crowding with small test-cells. The Scotia colony was evidently 

 taken at the reproductive season, as it contains abundance of embryos in various stages 

 of development up to the tailed larval stage ready to be set free. 



Amaroucium sp. (?). 



Some small colonies, a few millimetres to about 1 centimetre across, which were found 

 attached to groups of Styela paessleri and other Ascidians from the Falkland Islands, 

 belong to the genus Amaroucium, but may be only young colonies of some larger form 

 such as A. distomoides, or A. pallidulum obtained by the Challenger Expedition at 

 Port William. 



It may be remarked in regard to the three last species of Compound Ascidians that 

 they require re-examination in the living state. Many of the Compound Ascidians 

 are scarcely determinable from the contracted and bleached specimens in preserved 

 collections. It may well be that one or other of the above Polyclinids had in 

 the living state a bright colour or some other characteristic appearance that is now 

 wholly lost. 



THALIACEA. 



(MS. received March 13, 1912.) 



Family SALPID^;. 



The very large collections of Thaliacea, which were obtained at the South Orkneys 

 and other Antarctic localities (some from under the ice), were found on examination 

 to belong entirely to the genus Salpa and to represent two species only ; and in fact 

 all the specimens, except a single one, are different conditions and sizes of the common 

 and widely distributed species, Salpa runcinata-fusiformis. 



Salpa runcinata-fusiformis, Chamisso-Cuvier. 



Station 432, surface, March 30, 1904 ; temp. 31'8. Nearly one hundred specimens, 

 from 3 cm. to 6 cm. in length, all of the aggregated form, and many of the larger 

 ones showing echinated ridges on the test. Most of them showed embryos projecting 

 into the peri-branchial cavity, one in each. 



Station 427, from coarse tow-net, March 26, 1904. About one hundred specimens, 

 from 3 cm. to 5 cm. in length. In other respects they resemble those from the last 



(ROY. soc. EDIN. TRANS., VOL. XLVIII., 318.) 



