174 HYDROIDA II 



grandis^ first described from some colonies from Japan, Tsugor Strait, preserved at Copenhagen. The 

 species differs from the others by its longitudinally ribbed gonothecas; the other species in which the 

 gonangia are known, have the gonothecse transversely furrowed. The ne.xt find of Bo)nirvirlla grandis 

 was made off the west coast of Norway. We have since learned, that the species, besides occurring 

 at several places in tlie North Pacific, is also widely distributed in European waters. It has been 

 met with in the Barents Sea, at Lofoten (fig. LXXXIX), at Moldoen near Stat on the west coast of 

 Norway. It is mentioned from the south-east point of Iceland and from Fyllas Banke in Davis Strait. 

 We may now add some new localities; the Faroe Islands, and outside Isafjord, Iceland, where it was 

 taken by the "Michael Sars" in the summer of 1903. BoinicvicUa graiidix must thus be characterised 

 as a boreal circumterrestrial species, belonging to the lower parts of the littoral region and the upper 

 portion of the abxssal. 



HI. Addenda to the Athecate Hydroida. 



In going through the athecate hydroids, some few glasses were overlooked, and are here 



included. 



Corymorpha nutans M. Sars (Part I, p. 31). 



Iceland : Keflavik (depth not stated) 



Bredebugt 65°! 2,5' N., 23°28' W., depth 36 fathoms. 



Corymorpha groenlandica (A 11 man) I5roch (Part I, p. n). 

 "Ingolf" St. 15 66°i8' N., 25°59' W., depth 330 fathoms H- 0,75° 



This find forms an interesting complement to the former data (cf. Part I, text fig. I); it lies in 

 Danmark Strait, on the northern slope of the threshold, and shows that the species also occurs be- 

 tween Iceland and Greenland. 



Famil}^ Branchiocerianthidae. 



Athecate hydroids without calcareous .skeleton. The tentacles of the grown polyp, which are 

 all filiform, make two main circles; the tentacles have a central cavity not connected with the gastral 

 chamber. The supporting lamella exhibits no particular development in any of the tentacles. The 

 hydrauths are bilateral in structure. At the base of the proximal tentacles, numerous radial canals 

 occur, reducing ijic mesogloeal formations to a minimum. The gastral chamber is divided bv a hori- 

 zontal sejitum iuli) two part.s, a smaller proboscoidal, and a larger basal. The gastral endoderm is 

 homogeneous in l)olh. 



Gen. Branchiocerianthus Mark. 



The polyps are bilateralh- symmetrical, the stalk being excentrically attached; the oral aperture 

 also is excentrically situated, being thrust over towards the opposite side of the point where the stalk 



