110 1,. Koi.Di lu r l{()si;NviN(ii:. 



(.'crlMiiily Ix'tMi Iviiii; loose on llu" hollom; in somt' ol Ihcin Ihe 



uikKmihosI |);ui is in :i shile ol' disintegralion. l"or inosl ol" Ihe 



specimens Ironi Ihe harl)onr il has also l)een staled, Ihal Ihey have 



been dredged on soll bolloni. Some smaller specimens are however 



provided wilh basal disc. 



Loc. Alonj* Koldcwey Islaiid, 1.") inclcrs :iii(l deeper; l):iiiiii:iiks Ilavn, 

 7 11 meters, soft bottom. 



Actinococcus Kiilz. 



19. A. subcutaneus (Lyngb.) K. Rosenv. 



K. l^oscnvinge (IHSVA) p. 8'22. (18!»8 I) p. Xi; Jonsson (1904) p. 14. 



A large specimen of Pliijllophora Brodiœi *interrupta bears nu- 

 merous specimens of this much disputed alga attached lo the upper 

 margin of some of the one-year old segments. 



Loc. Along Koldewey Island, ca. 15 meters. 



Ceratocolax K. Rosenv. 



20. C.Hartzii K. Rosenv. 



K. Rosenvinge (1898 I) p. 34. 



Several specimens of Phyllophora Brodiœi *interrupta are infested 

 with Ibis parasite which is situated partly on the border partly on 

 Ihe flat side of the frond. The specimens of the parasite form small 

 bushes up to 3 mm. in diameter, fully agreeing witli the previously 

 found Greenlandic specimens; several of them bore nemathecia, but 

 the sporangia were still undivided in August. The specimens of 

 Phyllophora on whicli they were parasitic were certainly all loose- 

 lying when dredged. 



Loc. Danmarks Havn, 7—11 meters, Aii.i*ust. 



Choreocolax sp.? 



In a specimen of Eiithora cristaia fiom Koldewey Island were 

 found some cushions of a small parasitic Floridea looking much 

 like a Choreocolax or Harveijella. As there is not sufficient material 

 for a detailed description, I shall not menlioii it closer but only 

 state that it grows in the same manner as Harueyella and Choreocolax, 

 sending out from the underside of the cushion-shaped or nearly 

 globular frond filaments penetrating between the cells of the host. 

 In a dried state the parasite has a prettj' red colour. 



Fam. Helminthocladiaceœ. 

 (iiantransia (D. C.) 



21. Ch. effiorescens ( J. Ag.) Kjellm. 



K. Rosenvinge (1898 I) p. 40, (1909) p. 134. 



