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XVI.—The Tunicata of the Scottish National Antarctic Expedition, 1902-1904. 
By W. A. Herdman, D.Sc., F.R.S., Professor of Zoology in the University of 
Liverpool. (With One Plate.) 
(MS. received January 8, 1912. Read February 19,1912. Issued separately July 3, 1912.) 
So far as regards number of individuals, and their size, this is one of the largest 
collections of Ascidians brought back in recent years from Antarctic seas. It contains 
almost exactly the same number of species of Ascrptacra (Ascidixw Simplices + Ascidize 
Compositz) as the Discovery collection—viz. fifteen or sixteen—but whereas in the 
latter collection nearly all the species were represented by single specimens, in the 
Scotia collection most species can show long series of individuals—in all there are about 
two hundred specimens, as against the thirty-three brought home by the Discovery. 
The sixteen species in the present collection represent almost as many genera, and 
half a dozen families. The systematic arrangement is as follows :— 
ASCIDIACEA. Polyzoa opwntia, Lesson. 
Family Moteunipa. Goodsiria placenta, Herdman. 
Paramolgula gregaria (Lesson). - Family Ascrprpa. 
Paramolgula horrda (Herdman). Aactd Ree 
Family CyNrHip. ; 
: Family Distomip&. 
Colella pedunculata (Q. and G.). 
Holozoa cylindrica, Lesson. 
Boltena legumen, Lesson. 
Fungulus antarcticus, n. sp. 
Halocynthia setosa, Sluiter. 
Family SryELip&. Family PoLycLinip&. 
Styela lactea, Herdman. Polyclinum complanatum, Herdman. 
Styela paesslert, Michaelsen. Amaroucium distomoides, Herdman. 
Synstyela mcrustans, Herdman. Amaroucium sp. 
It is interesting to notice how greatly some of these recent collections from the far 
South differ from one another in the species represented. ‘The following table—which 
gives only the sixteen species in the Scotia collection—shows that only one form 
(Halocynthia setosa) from that collection was also taken by the Discovery, whereas ten 
species were taken by the Challenger, eight by the Hamburg Magellanic and South 
Georgia Expedition, and five by the French Antarctic Expedition under Charcot. This 
can be explained to some extent, at least, by the precise localities visited: the Scotia, the 
Challenger, and the Hamburg collections were largely made in the Magellan and Falk- 
lands neighbourhood, while the other three collections were mainly from farther south. 
TRANS. ROY. SOC. EDIN., VOL. XLVIII. PART II. (NO. 16). 47 
