x 62 HYDROIDA II 



not move far up into the fjord waters. This may possibly also account for the distribution of the 

 species within the area investigated (fig. LXXXIII). Campanularia Integra is very common along the 

 west coast of Greenland, but lacking on the east coast south of 76 N., according to what we know 

 up to the present. The remarkable paucity of hydroids — arctic or boreal, -- along this coast can- 

 not be explained as due exclusively to temperature conditions, but must doubtless, judging from Cam- 

 panularia Integra^ be partly occasioned by an accumulation of the fresh glacier water along the shore 

 in contrast to the west coast, where warmer atlantic currents occasion a livelier interchange of water 

 supply. A further peculiarity appears to lie in the scantiness of the species at the Faroe Islands; 

 this, however, may possibly be accounted for by the fact that zoological bottom investigations have 

 for the most part been made at greater depths than those at which the species chiefly lives in 

 these waters. 



Campanularia Hincksii Alder. 

 1856 Campanularia Hincksii, Alder, A notice of some new genera and species, p. 360 pi. 13, fig. 9. 



Creeping colonies, from the stolons of which proceed long hydrotheca stalks, more or less 

 distinctly ringed above their point of origin and under the hydrotheca; the stalk terminates below 

 the hydrotheca in a ball-shaped joint. The hydrothecae are very nearly cylindrical, with an evenly 

 curving, rapid transition from the bottom to the stalk. In transverse section, the hydrotheca is poly- 

 gonal, with eight to fourteen straight sides, each running out at the opening into a strong tooth, 

 transversely cut off; the teeth may also at times exhibit a slight median incision. The basal cavity is 

 small, bounded at the top by a sharply defined low and narrow ring-shaped thickening of the 

 inner wall. 



The gonothecre are attached directly or by a rudimentary stalk to the stolons. They are 

 elongated egg-shaped, broadest about the lower third, cut off transversely at the distal part, and with 

 more or less prominent transverse furrows. 



Material : 



Iceland: Vestmano, depth 28 fathoms. 



North Sea: 57°07' N., 2°40' E., depth 37 fathoms. 



Saemundsson (191 1 p. Jj) mentions under this species an instance m which an approach to 

 rhizocaulome formation was found, giving rise to a stem 1 cm high, whereby the colony assumed a 

 considerable resemblance to Campanularia vcrticillata. 



Campanularia Hincksii is a southern species doubtless more rare in northern waters than would 

 appear from the records extant. It has frequentlv been confused with Campanularia groenlandica, which 

 it somewhat resembles in a sterile state. Its occurrence in arctic waters is in reality very doubtful, 

 and we must await further data before we can decide its biogeographical character with any certainty. 



