HYDROIDA II 



131 



Jan Mayen, depth 50 — 60 fathoms (East-Greenland Expedition). 

 Iceland: Mouth of Berufjord, depth 41 — 54 fathoms. 

 Kara Sea, "Dijuijihua". 



Si-rtularia Juibricii is very closely related to Srrtularia cii/>nssi/iii, but differs priniarilv in its 

 dextrorse stem. Moreover, its hydrotheca; are as a rule more deeplv imbedded than in the latter 

 species (fig. LXIX). Levinsen (1S93 p. 48) calls attention to a peculiarity in the .species, to wit, that 

 the basal branches throw off their extreme parts, leaving only the proximal intcrnodinm; this appears 

 to be a characteristic feature in the species, the explanation of which caimot be arrived at from our 

 present knowledge of its biology; it gives the species a highly remarkable appearance. Another char- 



Fit?. LXX. Finds of Sfitiilaria Fahricii iu the Northern Atlanti' 



c. 



acter which has been emphasised is less reliable; according to Ivcvinsen, the upright direction of 



the branches is 45° with the longitudinal axis of the stem; but the colonies from Jan Mayen and 



from the -'Ingolf" St. 2 had branches standing out almost perpendicularly from the stem, and farther 



out even turning downwards; in these colonies also, the tendency to unilateral arrangement of the 



hydrothecas is remarkably slight; despite this, and despite the fact that they arc of finer build than 



those from Greenland, they cannot be regarded as types of a distinct .species. 



It is interesting to note how exactly the hydrothecas in Scrinlaria luihricii follow the same 



rules in their variation as in Srrtularia cuprcssina. On the proximal part of the branches, the liydro- 



thecte are far more deeply imbedded than at the extremities (fig. LXIX). The gouothecie, on the 



other hand, evince a much slighter variational tendency in the present specimens, which rather give 



17* 



