44 



HVDROIDA II 



Upright colonies with polysiphonic, irregularly ramified main stem, and regular singly or 

 doubly pinnate branches; the outer, minor branchlets regularly alternating. The hydrothecse small, with 

 expanded margin, especially on the adcauline side; the basal cavity is large, somewhat asymmetrieally 

 developed, with a markedly convex adcauline wall and a straight or slightly concave abcauliue wall, 

 inserted asymmetrically on a laterally placed apophyse at the distal end of the internodium. The 

 branches are divided into internodia, which often exhibit one or two basal constrictions. 



The gonothecte proceed from the tubes of the stem. They are large, somewhat flattened, and 

 furnished with spiny longitudinal ribs on the flat side. 



Material : 



"Ingolf" St. 29 65°34' N., 54°3i' W., depth 68 fathoms 0,2° 



- 34 6 5 °i 7 ' N, 54°i 7 ' W, 55 



- 84 6 2 ° 5 8' N, 25*24' W, - 633 4,8° 

 "Thor" 65°52' N., 23°58' W., — 62 metres 



64°i6' N., 22°i7' W., - 50 — 

 6 4 °i6' N, ii°i 5 ' W, 37S - 



Greenland: Egedesmiude (without further details) 



Store Hellefiskebanke ( — — ) 



Store Hellefiskebanke depth 24 fathoms 



Davis Strait ( — — — ) — 100 — 



Ingmikertok, Augmagsalikfjord (East Greenland Expedition) 

 Iceland: Mouth of Hornafjord (depth not stated) 

 Rodefjord, depth 80 fathoms 

 Djupivogr — 8 — 

 Vestmano — 10—15 — 

 10 miles W. of Akranes (depth not stated) 

 Stykkisholm, depth 30 fathoms 



Bredebugt 65°i7' N., 23°32' W., depth 7—12 fathoms 

 Adelvik (depth not stated). 

 The Faroe Islands: 7 miles N. by E. of Myggemes point, depth. 57 fathoms 

 6 miles N. by W. of Store Kalso, — 60 — 



Deep hole at north point of NolsS — 100 — 



5 miles SSE. of Bispen — 50 — 



Forma abyssal is: 



"Ingolf St. 125, 68°o8' N., i6°02 r W.; depth 729 fathoms, — o,8° 



Halecium muricatum, witli its asymmetrically developed hydrotheca stalks or basal cavities 

 and its slenderer form, stands out distinctly from the remainder of the northern Halecium species, and 

 is not easily confused. It is as a rule finely built, but may occur in large colonies with highly rami- 

 fied polysiphonic main stem; the ramification then mostly proceeds in a main plane, but can also be 

 altogether irregular, so that the colonies assume a quite bushy appearance. The margin of the hydro- 



