HYDROIDA 1 1 



169 



Sterile colonies of this species with almost or entirely smootli margin may at times present a 

 certain resemblance to Laoiitfdca flrxuosa, and have freciueiitly been confused with this species by 

 Ssemnndsson. — Nutting- (1915 p. 73) endeavours to revive Obclia flabrllata Hincks on the ground 

 that the extreme branches of this species exhibit dichotomous ramification, whereas in the present 

 species they are "flabellate"; unfortunately, however, he does not further explain the difference between 

 the two terms. In the present colonies, both might often apparently be applied to the same branch. 

 Nor does his other distinctive character, the fact that the branches in Obclia longissima are "regularly 

 alternate" while those in Obclia flnbcUata are "alternate or opposite" give us any sound basis to work 

 on. Bonnevie (1899 p. 71) is undoubtedly right in uniting the two .species, and they cannot be 

 revived on the strength of what Nutting here seeks to show. 



Laoiiicdca lo)igissii/ia appears to be a cosmopolitan species, albeit the data on record from 

 tropic-subtropical waters are but scant>'. The species belongs to the upper third of the littoral region, 

 and goes far up into arctic waters, where it has a circumpolar distribution. In the area investigated 

 (fig. lyXXXVI) it appears to be entireh- lacking in East Greenland waters, but is otherwise fairly re- 

 gularh- met with on all coasts. 



Laomedea hyalina (Hincks) Levinsen. 

 1866 Gonothyrcra /lyalitia, Hincks, On new British Hydroida, p. 297. 

 1893 Laomedea — Levinsen, Meduser, Ctenophorer og Hydroider, p. 28. 



Finely built upright colonies with monosiphonic main stem, the latter being, like the main 

 branches, generally brown in colour. The colony often assumes a bushy appearance, owing to irre- 

 gular ramification. The liydrothecse are carried on short ringed stalks proceeding from the branch 

 apophyses; the latter are set in a plane on the branch directed alternately to either side. The liydro- 

 thecse are slender, in\'ersely conical to cylindrical, tapering somewhat more at the basal part toward 

 where the stalk begins; they are twice to tliree times as long as broad. The hydrotheca margin is 

 furnished with low teeth, having a slight, often almost imperceptible median sinus in their distal 

 end, which is cut off almost straight, so that they are divided into two denticles; from this sinus a 

 slight furrow runs for a var\'ing distance down the ludrotheca on its outer side. The basal chamber 

 is small, bounded at the top by a thin, but well developed diaphragm. 



The gonothecse are borne on short, ringed stalks, proceeding from the ajjophyses beside the 

 hydrotheca stalks. They are inversely conical, cut off straight at the distal end, without neck. The 

 gonophores develope into crypto-medusoid mecouidia, which extend out from the gonotheca without 

 breaking awa)-; the larval development takes place in the interior of the meconidium. {Gotiofiiyrcpa 

 meduste). 



Material: 



"Ingolf" St. 34, 65°i7' N., 54"'i7' W., depth 55 fathoms. 



"Thor" 66°23' N., i4°24' W., — 45 metres 



— 65°52' N., 23°58' W., — 62 — (labelled Laomedea L.oveni\ 



— 64=16' N., 22°i7' W., - 50 



Tile Ingolf-Expeiiiiion. V. 7. 



