1912-13.] Hydroids of British Antarctic Expedition, 1908. 29 
siphone Stamme” (Hartlaub, 1900, p. 33). And Vanhoffen himself regards 
his own specimens as “ sehr ahnlich der vorigen [Sertularella glacialis ] in 
Wuchs ” (Vanhoffen, 1909, p. 326). But the stem of Sertularella glacialis 
is monosiphonic, and many colonies are aggregated in an entangled mass. 
The habit of Sertularella cumberlandica, with fascicled stem and branches, 
is very different from that of the species described in the above quota- 
tions, as a glance at Jaderholm’s figures shows. Further, the free por- 
tions of the hydrothecse of Sertularella cumberlandica lie more closely 
against the internode than do those of Sertularella subdichotoma, and the 
axis of the distal half is seldom at a pronounced angle with that of the 
proximal, as is the rule in the latter species. 
I retain, therefore, Jaderholm’s Sertularella^ cumberlandica, regarding 
it as a species distinct from Sertularella subdichotoma. 
Sertularella glacialis, Jaderholm. 
Sertularella glacialis , Jaderholm, 1904, p. 9 ; 1905, p. 26, pi. x. figs. 3-7 ; but probably 
not Sertularella glacialis , Vanhoffen, 1909, p. 325, fig. 40. (See fig. 10, p. 32.) 
From various localities near Cape Boyds come intertangled clumps of 
colonies with simple stems and branches, and very pronounced nodes, which 
seem to me to belong to this species. Unfortunately, there is no gonosome 
present, but, for the rest, the lax habit of growth, the structures of inter- 
nodes and hydrothecse, the proportions of the latter — “ half or more than 
half free from the internode,” — the colour of the colonies as preserved in 
alcohol — “brown to dark brown,” — these characters agree with those 
described by Jaderholm, as do our specimens with his figures (see fig. 10, 
p. 32). Our specimens, however, are slightly larger in size than those from 
the Graham Region, as comparison of Jaderholm’s measurements with those 
given below shows. 
Dimensions . — 
Internode, length 
diameter 
Hydrotheca, length adnate . 
„ free 
diameter at mouth 
064-1T5 mm. 
0T4-0T6 mm. 
0-20-0-27 mm. 
0-24-0*30 mm. 
0-17-0-20 mm. 
Localities. — Cape Boyds, 10 to 25 fathoms, July 1908, rare; 30 to 60 
fathoms, 15th August 1908 ; 30 to 80 fathoms, August 1908, rare. 
Distribution. — Sertularella glacialis is known only from Antarctic 
seas, within which it has now been found on both sides of the Antarctic 
continent. Previous record : Graham Region, Seymour Island to Cape 
Seymour, 150 metres (Jaderholm). 
