146 



HYDROIDA II 



genus Thujaria, as I have already (1909 p. 222) placed it. The same genus, however, has formerly 

 been made to include Sertularia arctica Allman and Sertularia arctica Thompson, which is incorrect. 

 The proper method of proceeding here will be to alter the name of the present species, as being of 

 later date, and this I have accordingly done, naming it, from the variable character of the branches, 

 Thuja ria va ria b/lis. 



Thujaria variabilis has only occasionally been found in arctic waters near Beereu Island, at 

 Spitzbergen and off the Murman Coast at 38 to 86 metres' depth. Reydarfjord thus represents the 

 most southerly find, and is also, with its 80 fathoms, the deepest. 



Thujaria lonchitis (Ellis and Solander) Fleming. 



1786 Sertularia lonchitis, Ellis and Solander, The natural history of many curious and uncommon 



Zoophytes, p. 42. 

 1828 Thujaria articulata, Fleming, A History of british animals, p. 545. 

 nee 1766 Sertularia articulata, Pallas, Elenchus Zoophytorum, p. 137. 



1847 Thujaria articulata, Johnston, A History of the British Zoophytes, p. 84, pi. 18, figs. 3 — 4. 

 nee 1851 — Busk, A list of Sertularian Zoophytes and Polyzoa from Port Natal, Algoa 



Bay , p. 119. 



1868 ■ — pars, Hincks, A History of the British Hydroid Zoophytes, p. 277, pi. 60. 



1874 — G. O. Sars, Bidrag til Kundskaben om Norges Hydroider, p. 106. 



1884 — lonchitis, Kirchenpauer, Nordische Gattungen uud Arten von Sertulariden, p. 24, pi. 14, 



% 7- 

 (nee 1884 — articulata, Kirchenpauer, 1. c. p. 26, pi. 14, fig. 8.) 



nee 1888 — pectinata, Allman, "Challenger" vol. 23, p. 69, pi. 33, fig. 1. 



1890 — lonchitis, Marktanner-Turneretscher, Die Hydroiden des k. k. naturhistorischen Hof- 



museums, p. 236. 



I §93 — — L-evinsen, Meduser, Ctenophorer og Hydroider, p. 53. 



1899 — articulata pars, Bonnevie, Den norske Nordhavs-Expedition, p. 84. 



1904 — lonchitis, Nutting, Sertularidae, p. 66, pi. 9, figs. 5 — 8. 



1909 — kolaensis, Jaderholm, Northern and Arctic Invertebrates, p. 88, pi. 8, figs. 17 — 18. 



71909 — lonchitis, Jaderholm, 1. c. p. 89, pi. 9, fig. 3. 



1909 Broch, Die Hydroiden der arktischen Meere, p. 174. 



The upright colonies are as a rule pinnate throughout their entire length, more rarely with a 

 spirally coiled distal part of the monosiphouic stem. In the pinnate portion of the colonies, the broad 

 plane of the branches is vertical, in the spiral horizontal; the branches form almost a right angle with 

 the' stem, which is dark in colour. The stem is segmented in its lower part, but in the upper, the 

 segmentation becomes almost entirely effaced; the branches are subalternately to alternately set. The 

 stem has two rows of hydrothecse; between two successive branches on the same side of the stem 

 there will be two to three, rarely more (up to five) hydrotheca;, the lowest in the angle of the branch. 

 The branches are not generally ramified, but may more rarely exhibit secondary dichotomous ramifi- 



