n8 



HYDROIDA II 



The Faroe Islands: 8 — 10 miles N. of the Faroe Islands (without further details) 



6 miles N. by W. of Store Kalso, depth 60 fathoms 



7 N. by E. of Myggenaes point — 57 

 Boronses i3/ 4 miles in N. 75° W. 30 

 Deep hole at north point of Nolso - 100 



13 miles W. by S. of Munken 



— mo 



I have in earlier works (1908, 1909) united this species with the next, the more finely built 

 form Abictinaria tiliatla (Ellis et Solander), having oyerlooked the specific character which lies in the 



200 rti. _6oom. ._iooom. 2ooom. 



Fig. LX1I. Tile distribution of Abieiinaria abietina in the Northern Atlantic. 

 In the hatched regions a common occurrence is reported. 



peculiar diaphragm of Abieiinaria abietina, as pointed out by Levinsen (1893 p. 56). Generally speak- 

 ing, the robuster stucture of the colonies will obviate any doubt when dealing with the last-named 

 species, but this is not always the case. Occasionally, Abieiinaria abietina may assume a finer struct- 

 ure (cf. Broch 1908) and it was from observation of such doubtful colonies that I was led to combine 

 the two species under a common name. In such dwarf colonies, however, identity may easily be deter- 

 mined by examination of the diaphragm, which in Abieiinaria abietina is typically bilateral, whereas 

 in Abietinaria tit/fata the development is almost entirely radially symmetrical. 



Abietina rin abietina is a circumpolar boreal species, capable of penetrating far into the arctic 

 area, albeit its occurrence there is more sporadic. It can also move far to the south, and is found 

 in the Mediterranean and at Madeira. It belongs really to the littoral region, but mav exceptionally 



