HYDROIDA II ~- 



Material : 



"Iiigolf" St. 7, 63°i3' N., i5''4i' W., depth 600 fatlioms, 4,5° 

 - - 9, 64°i8' N., 27°oo' W., - 295 - 5,8° 



- 54, 63''o8' N, i5°4o' W., - 691 - 3,9° 



"Thor" 63^30' N., 20°i4' W., — 80 metres — [labelled Haleciutn halecimim^ H. 



Beaiiii and //. lahrosuni]. 

 Greenland: Cape Tobin, depth 57 fathoms (East Greenland Expedition). 

 Iceland : Vadlavik (depth not stated) 



Vestmano, depth 30—40 fathoms [labelled Haleciiim /la/rciumn and //. Bcanii\ 

 10 miles W. of Akranes (depth not stated) [labelled Halcciiun Braiiii\. 

 Between Iceland and The Faroe Islands, depth 192 fathoms (without further details) 

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

 Stokken 2 miles in S.22E., — 55 — 

 Deep hole at north point of Nolso, depth 100 fathoms. 

 Glyversnass near Thorshavn, on red algae. 

 Boronces 13 miles in N.75W., depth 30 fathoms. 



Halccium haleciiuoii is generally of somewhat coarser build than UaLcmni Bcanii^ but a good 

 deal finer than Haleciiim sciifiiii/\ it is often extremely difficult to distinguish these species one from 

 another, especially when the colonies assume an altogether irregular form, which 

 the males in particular are inclined to do. The female gonotheca; in Hahcium 

 halecininii will, in their normal shape, with the quite terminal lateral opening, 

 hardly be confused with normal individuals of the other species, but when, as not 

 infrequently occurs, the distal portion of the gonotheca is domed forward, so that 

 the aperture is found somewhat below the point on one side of the gonotheca, 

 the identity is bv no means eas\- to determine. True, Hnleciuni sciitiini is in 

 most mstances of far coarser build than the two others, but the variation in dim- 

 ensions is within each of the three too great to permit the fixing of proper size 



Fig. XI. Hatecmm hale- 



limits; they would be found to overlap considerably. A useful general character ,■„,„,«. intemode with 



for Haleciiim halecinum is the asymmetrical development of the basal cavity in hydrotheca;. From the 



^ ■ Faroe Islands at north 



the secondary hydrotheca (fig. XI); the basal part of the adcauline wall is more point ot Nolso. (x 60). 

 strongly developed, and highly curved, so that the hydrotheca axis thus diverges widely from the 

 branch. On the other hand it must be remarked that the hydrotheca aperture is perpendicular to the 

 longitudinal axis, a feature whereb\' the species is distinguished from Haleciiim Beanii. 



Haleciiim /laleciiiiim has an extremely wide area of distribution, and is very common right up 

 in the Mediterranean; it has also been recorded from waters south of the Equator. In the northern waters, 

 the species appears as a boreal character form, with warmer tendency (fig. XII) and is mostly met 

 with in the middle part of the littoral region; at times, however, it may penetrate right down into 

 the abyssal, as at the "Ingolf" St. 54, where it was taken in a depth of o\er 1300 metres. In purely 

 arctic waters, it is very rare, and records of its occurrence there must be treated as doubtful, as it 



