HYDROIDA 11 jQQ 



"Thor" 66°i9' N., 23°27' W., depth 115— 120 metres. Variety. 

 - 65^52' N., 23°58' W., _ 62 - 



63=30' N., 20° 1 4' W., — 80 — 



Greenland: Davis Strait, — 100 fathoms (without further details) 



Iceland: 5 miles E. of Seydisfjord, — 185 — 



Ingolfshofdi g'/. miles in N. by E.'/aE. (depth not stated) 

 Vestmano, depth 50 fathoms 

 Skagi, — 40 metres 



6 miles W. of Iceland (without further details) [labelled Diphasia rosacea] 

 0nundarfjord, depth 10 fathoms [ — — — | 



65°39' N., 28°25' W., depth 553 fathoms. 

 Between Iceland and The Faroe Islands: depth 270 fathoms (without further details). 

 The Faroe Islands: 8 — 10 miles N. of The Faroe Islands ( — — — ) 



7 miles N. by E. of Myggenses point, depth 57 fathoms 

 6 — N. by W. of Store Kalso, — 60 — 



• Deep hole at north point of Nolso, — 100 — 



Boronses 13 miles in N. 75°W. — 30 — 



16 miles E. by S. of south point of Nolso — 80 — 



It may be a question whether Dipliasia fallax cannot exceptionally be confused with Dipliasia 

 Wandeli Levinsen, if the latter species, as Ssemundsson opines, can occur with only two rows of 

 hydrotheca; on the branches. There are also in the present material colonies of Diphasia fallax dif- 

 fering in appearance, so that there is some ground for further considering the point. 



Ssemundsson (1911 p. 97) mentions having found colonies of Diphasia IVa/idrli with only two 

 rows of hydrothecae on the branches, and with female gonothecte, which, however, from his drawings, 

 agree entirely with Diphasia fallax. According to a footnote in Seem un dsson's work (1911 p. 98) 

 Levinsen should, after seeing the colonies, have expressed as his opinion that they must rather be 

 regarded as aberrant colonies of Dipliasia fillax than as representatives of Diphasia Wandeli Now 

 Ssemundsson points out, in the same place, that a colony of Diphasia Wandeli from the Norwegian 

 Sea, which he has had occasion to study, had on the basal parts of eight of its branches only two 

 rows of hydrothecse, while the outer parts of these branches, and all the remaining ones throughout 

 their length, had three rows of hydrotheca;. This reminds one not a little of the aberrant Tliujaria^ 

 which is further described in "Fauna artica" (Broch 1909 p. 177). As the colony described by Sa;- 

 mundsson is sterile, it cannot be determined with certainty. It is probably a Diphasia Wandeli., but 

 it might also be imagined that it could be a mutant of Diphasia fallax^ though this is less likely to 

 be the case. Typical female colonies of Dipliasia Wandeli with gonothecae have not yet been found; 

 as to the males, we know that the\- differ from Diphasia fallax in having eight instead of four distal 

 spines on the gonothecfe, these eight spines being arranged in pair.s. It is therefore impossible to say 

 with certainty which species Ssemundsson had before him, as long as typical and fertile female 

 colonies of Diphasia Wandeli have not yet been found. Ssemundsson's colonies form, moreover, 

 only the extreme link in a continuous variation series, of which the central one is Diphasia fallax. 



