8 JÄDERHOLM, NORTHERN AND ARCTIC HYDROIDA FROM THE SWEDISH ZOOLOGICAL STATE MUSEUM. 



Thujaria läxa Allm. 



The material consists of four old and three young colonies and also several 

 fragments. The first-mentioned specimens have dichotomous branches, spirally ar- 

 ranged in the distal part of the colony, while the proximal part is destitute of 

 branches. Hydrothecae wholly immersed or nearly so; the free adcauline part ne ver 

 half the diameter of the hydrotheca-mouth. Gonothecae wanting. 



Localities: Arctic Sea of Sibiria, 76° 8' N., 90° 25' E. (Vega-Exped.); Kära Sea, 

 74°12'N., 75°45'E. and 74°45'N., 71° 6' E. at a depth of 16—18 fathoms, 3 / 8 1876 

 (Nordenskiölds Exped.); Novaja Semlja, Matotschkin Sharr, Gubin Bay, clay, 5 — 15 

 fathoms, 10 /s 1876 (Nordenskiölds Exped.); Spitzbergen, Lovens Mountain, 35 fathoms, 

 stones and clay, "/t 1868 (Sw. Spitzb. Exped.). 



Thujaria alteruitheca Lev. 



Localities: Greenland, Baffin's Bay, 67° 59' N., 56° 33' W., 98 fathoms, stones 

 and mud, 2fi A 1871; Davis Strait, 65° 11' N., 53° 33' W., 48 fathoms, clay, 13 / 6 1871: 

 The Banks of Newfoundland, 45° 53' N., 51° 56' W., 50 fathoms, stones and shells, 

 16 7s 1871. Represented in nine colonies up to 25 cm high. Gonothecae frequently 

 present. All the specimens are collected by Dr. J. Lindahl. 



Sertularia Fabricii Lev. 



Distal branches on all sides of the stem, forming a dense tuft, proximal branches 

 wanting. The hydrothecae agree exactly in size as well as in character with the 

 form of this species described and illustrated by Levinsen and also with the spe- 

 cimen from Greenland, which I have had occasion to examine. 



Localities: Greenland, Disco, Nordfjord, 27 fathoms, härd, grey clay, 10 /t 1871; 

 Davis Strait, 65° 11' N., 53° 33' W., 48 fathoms, clay, 1S U 1871. All the specimens 

 collected by Dr. J. Lindahl. 



Sertularia plumosa (Clarke). 



Locality: Bering Sea, 64° 30' N., 171° 45' W., 25 fathoms, stony bottom, 31 /7 

 1879 (Vega-Exped.). Only small sterile fragments collected. 



Sertularia cuuressiua Lin. 



Localities: Kära Sea, 74° 12' N., 75° 43' E., 18 fathoms, loam, 3 /s 1876 (Nor- 

 denskiölds Exp.); Murman Sea, Lumbowski, at a depth of 21—37 fathoms, 9 / 8 1877 



