HYDROIDA II 



I05 



._ 1000 m. 



Fig. LVI. Finds of Sertularella tenella in the Northern Atlantic; 

 In the hatched regions the data are not altogether precise, (o doubtful locality. 



Sertularella fusiformis Hincks. 

 1861 Sertularia fusiformis, Hincks, A Catalogue of the Zoophytes of South Devon, p. 253, pi. 6, figs. 7 — 8. 

 1868 Sertularella fusiformis, Hincks, A History of the British Hydroid Zoophytes, p. 243, pi. 47, fig. 4. 

 1907 Sertularella pellucida, Jaderholm, Uber eiuige nordische Hydroiden. 

 1909 Sertularella pellucida, Jaderholm, Northern and Arctic Invertebrates, p. 99, Taf. 11, figs. 8 — 11. 



Open and finely built, zigzag and slightly branched upright colonies with monosiphonic stem. 

 The stem and branches are divided into short internodia which form an angle one with another, and 

 are more or less distinctly ringed, more rarely quite smooth. From the same internodium may often 

 proceed two or three branches, or simple internodia. The large, somewhat spindle-shaped hydrothecae 

 are situate on the outer half of the internodium, and are very slightly embedded; the opening part 

 is again as a rule somewhat expanded; the aperture is set perpendicularly to the axis, and has four 

 not very prominent teeth, between which are attached four triangular lid plates. 



The gonothecae are attached to the branches or stolons. The}- are elongated oval to egg- 

 shaped, in the latter case with the broader part somewhat below the middle. The gonotheca has a 

 distal central aperture with four strong teeth. 



Material: 



"Ingolf St. 3 63°35' N., io°24' W., depth 272 fathoms, 0,5°. 



The Ingolf-Expedition. V. 7, M 





