Report on the Hydroids. 373 



figure (29). — JÄDERHOLM (1907 (50)) mentions and figures some 

 very large hydrothecae (1.02 — 1.08 mm.), which on account of their 

 obhque form he refers to L. friiticosa ; the description and the figures 

 correspond completely to the above-mentioned specimens from the 

 Danmark Expedition, and like these belong undoubtedly to L. grandis. 



Some of the colonies from St. 71 a occur on a leaf of Delesseria, 

 intermingled in a thick matting of Toichopoma obliqinim. 



Hab.: St. 71 a, 96. 



Depth: 30—180 m., most frequent at 160—180 m. 



G e о g r a p h i с a 1 d i s t r i b u t i о n : Arctic : Greenland, Iceland, Nor- 

 wegian Sea, Barents Sea. — Western Europe as far as Morocco. 



Not earlier known from East Greenland. 



Lafoëa serpens (Hassall) Bonnevie. 

 Plate XX, fig. 8. 



Campanularia serpens Hassall 1848 [25] p. 2223. 



,, „ 1852 [26] „ 163. PI. XXI, fig. 4. 



Reticularia „ Alder 1856 [1] „ 130. 



Filellum „ Hincks 1868 [28] „ 214. PI. 41, fig. 4. 



Lafoëa „ Bonnevie 1899 [13] „ 63. Tab. V, Fig. 4. 



Filellum „ Jäderholm 1909 [35] „ 76. Taf.VII, Fig. 11. 



„ Broch 1909 [17] „ 160&210. Textfig.21. 



„ „ Sæmundsson 1911 [55] „ 85. 



This widely distributed species is very abundant at several 

 stations, in the main on hydroids. 



Renovation of the hydrothecae may occur up to 3 times; the 

 treely projecting part of the new hydrothecae is of very variable 

 length and often crooked in another direction than the primary 

 hydrotheca so that the planes of the old and new aperture form a 

 considerable angle лvith each other. 



Not rarely the stolon rises from the support and forms an erect 

 stem, which may even ramify and bear many hydrothecae (see p. 358 — 

 359 and PI. XX, fig. 8). 



Gonosomes only observed on material from St. 68 a. 



There does not seem to me sufficient reason for retaining Filel- 

 lum serpens as a separate genus. The decumbent, growing part of 

 the hydrotheca may be so short, that great similarity with Lafoëa 

 dnmosa arises, and that the stem is creeping or almost always so is 

 an insufficient generic character, especially among these forms where 

 the erect stem is a rliizocaulus. Through Lafoëa dumosa, Filellum 

 serpens is so nearly related with the genus Lafoëa, that it should 

 be included in the latter. 



27* 



