140 



HYDROIDA II 



Iceland: Danmark Strait 66°2o' N., 25°i2' W., depth 96 fathoms 

 Adalvik, depth 5,5 fathoms (on roots of Laminaria). 



The Faroe Islands: 6 miles N. by W. of Store Kalso, depth 60 fathoms 

 Vestmanhavn (depth not stated) 



Deej) hole of north jDoint of Nolso, deistli 100 fathoms 

 16 miles E. by S. of south point of Nolso, depth 80 fathoms 

 Boronses 13 miles N. 75 W., depth 30 fathoms. 



Quite young colonies of T/m/aria thuja are pinnate, and very difficult to distinguish from small 

 colonies of Tlntjarin laxa AUman. The broad plane of the branches in such specimens, up to a couple 



Fig. I,XXV. The di.stributioii of Thujarm thuja in the Northern Atlantic. 

 In tlie hatched regions a common occurrence is recorded. 



of centimetres high, is vertical, and the branches are single. Here, however, the hydrotheca at the 

 tip of the branch, wliich is of the Scrlitlaria type, will as a rule reveal the identity of the species. 

 The occurrence of this type of hydrotheca in Thiijaria thtija is, as I have previously pointed out (1905) 

 of considerable interest, as giving us a hint of the derivation of the Thnjaria species from Scrhilaria. 

 Thujaria tinija is a boreal species, capable of moving far to the south; it is said to have been 

 found both off the coast of Portugal and in the Mediterranean, but is not common south of Ireland. 

 On the other hand, it docs not cuter the purely arctic waters; it has its chief distribution in the deep 

 littoral region, but may occasionally be met with in the abyssal, and even deep down in the same, 

 as is seen from the finds of the "Ingolf" at St. 95 and 96. In the North Atlantic (fig. LXXV) the 



