HYDROIDA 11 



II 9 



penetrate down into the abyssal. In northern waters (fig. LXII) it is extremely frequent along the 

 coast of Norway, round the British Isles, at the Faroe Islands and along the east, south and west 

 coasts of Iceland but very rare on the north coast of the same. Along the east coast of Greenland 

 it does not appear to have been found, but it is met with again from several parts of West Green- 

 land. It is remarkable that it should not be represented in the large amount of material collected by 

 the "Ingoif" expedition, but the explanation must presumably be that the species does not often live 

 far from the coasts. 



Abietinaria filicula (Ellis et Solander) Ki rchenpa u er. 

 1786 Sertularia filicula^ Ellis and Solander, The natural history of many curious and uncommon Zoo- 



phytes, p. 57, pi. 6, figs, c, C. 

 18S4 Abietinaria Jiiicula, Kirchenpauer, Nordische Gattungen und Arten von Sertulariden, p. 29. 



Finely built pinnate colonies, the branches often secondarily ramified pinuately in the same 

 plane as the main colony. Stem zigzag, with paired subalternating hydrothecse in two opposite rows. 

 There are as a rule three, more rarely four hvdmtheege between two successive branches on the same 

 side of the stem, the lowest in the branch angle. The hydrothecse of the branches also are arranged 

 subalternately in two rows. The hvdrothecse have a swollen basal part, narrowing upwards, and with 

 a slightly expanded opening margin; the opening plane is almost perpendicular to the branch axis. 

 The opening margin lacks adcauline sinus, and has a large adcaulinally fastened opercular plate. The free 

 distal part of the adcauline wall about half as long as the hydrotheca, and twice the opening diameter. 

 The distance between two successive hydrothecse on the same side is about equal to the length of the 

 hydrotheca. The diaphragm is almost radially symmetrical, with circular aperture. 



The gonotheca; arise close under the base of the hydrothecse, and are as a rule set on the 

 upper side of the branches. They are oval, with rudimentary stalk, and have a broad, short cylin- 

 drical neck. 



Material : 



"Thor" 65°52' N., 23°58' \V.. depth 62 metres 



- 6 4 °o 2 ' N, 22*33' W, - 34 — 

 Greenland, on ascidiae (without further details). 

 Iceland: Bakkefjord, depth 25—32 fathoms 



