130 



HYDROIDA II 



be more common in the Scottish waters than is generally supposed from the data obtained; he con- 

 siders it likely that it may have been confused with young colonies of Sertiilaria argcniea. This sup- 

 position will probably prove correct, as the species is fairly common along the west coast of Norway, 

 and penetrates right down to Bohuslan. It is also not uncommon at the Faroe Islands and Iceland; with 

 regard to the latter locality, it is scarce on the south coast, and apparently not very frequent on the 

 north. From East Greenland, it is known only by a single find far to the north, whereas it has been 

 met with several times in West Greenland waters. (Fig. L,XVIII). 



"-^'( 



Sertularia Fabricii Levinsen. 



1893 Sertularia Fabricii^ Levinsen, Mediiser, Ctenophorer og Hydroider, p. 48, pi. 6, figs. 14—17. 



Upright colonies with not very pronounced, monosiphonic stem, the hydrothecse and branches 



forming dextrorse spirals. Of the basal branches, only the basal internodium is retained, the remainder 



falling away. The stem is divided into internodia, each bear- 

 ing a basal branch, alternating in each of the two h\dro- 

 theca series; between two successive branches in the same 

 hydrotheca series the stem has normally three hydrothecre 

 the lowest in the branch corner. The broad plane of the 

 branches is horizontally set. The branches are secondarily 

 ramified dichotomically, and divided into internodia of \'ary- 

 ing length. The hydrotheca; are set in two rows, sub- 

 alternately or alternately placed; they are deeply imbedded 

 the free part of the adcauline wall is between one-third and 

 one-sixth the length of the hydrotheca, or between one-half 

 a I, and one whole opening diameter. The distal part of the hv- 



Fig. I.XIX. Sertularia Fabricii from Godthaab, drotlieca diverges ouh' slightly from the axis of the branch 

 a Hydrothecce from the distal part of a branch. 

 b Hydrotheca from the proximal internodium of On the Spiral branches, the hydrothecte tend more or less 



le same. (X 4°). towards Unilateral arrangement on the upper side of the 



branch. The hydrothecce are of equal breadth in their imbedded part, and narrowing sHghtly in the 

 free portion towards the opening; the margin of the latter has two short and broad lateral teeth; the 

 abcauline opercular plate has a large free distal part. 



The gonothecae proceed from below the base of the hydrothecse on tlie upper side of the branch. 

 They arc slender, reversely conical, somewhat flattened in transverse section, the narrow sides as a 

 rule running out each into one short, strong tooth; more rarely, one tooth — or both — may be 

 lacking. The gonothcca has a broad distal aperture, furnished with a short, often rudimentary cy- 

 lindrical neck. 



"Ingolf .St. 2, 63''o4' N., 9°22' W., depth 262 fathoms 5,3° 



- - 3> 63°35' N., io"24' W., - 272 - 0,5° 



— - 4, 64°07' N., ii°i2' W., — 237 — 2,5° 

 Greenland: Store Hcllcfiskebanke, depth not stated 



Godthaab, (lejith 30—40 fathoms Lev in sen's type specimens. 



Julianehaab, depth not stated 



