16 SYDNEY J. H1CKSON AND F. H. GRAVELY. 



Specie* B. 

 (Plate III., fig. 17.) 



Localities. W.Q., Hut Point, November 13th, 1902. W.Q., Hut Point, 

 September 27th, 1902. East end of the Barrier, January 29th, 1902; 100 fins. 



Three specimens of a solitary (?) coryuiform hydranth were found in the 

 bottles containing hydroids from these localities attached to the sponge spicule 

 debris. The hydrocaulus is 3 5 mm. in length. The hydranth is 2 mm. in height 

 and 0'6 mm. in diameter, cylindrical in shape, with short scattered capitate 

 tentacles 3 mm. in length. The proximal end of the hydrocaulus is covered by a 

 chitinous perisarc and gives off 3 or 4 hydrorhizal filaments (fig. 17, hrh. /.), for 

 attachment to the sponge spicule debris. No gonophores are present. 



Bonnevie describes a solitary form, Coryne gigantea, from Hammerfest (7 : p. 15), 

 but this species differs from our specimens in having a hydrauth longer than the 

 hydrocaulus and in having the tentacles arranged in groups of three or four 

 instead of singly. 



There is some reason for believing, from the evidence afforded by these 

 specimens, that at least two species of Corynidae occur in the Antarctic Sea. 



This is an interesting conclusion, as no specimens of the family were obtained 

 by the ' Belgica ' or ' Challenger ' expeditious, nor has the family been discovered 

 yet in the Falkland Islands. Hartlaub (10 : pp. 505-509), however, describes two 

 species of Coryne, one species of Syncorym and one species of Gemma ria from the 

 coasts of Chili, etc. 



It is also noteworthy that these few specimens are the only Hydrozoa in the 

 collection with capitate tentacles ; it is therefore quite certain that they are not detached 

 zooids from other large colonies that we have found in the collection, and improbable 

 that they represent initial stages in the life history of these large colonial forms. 



^1 FAMILY CORYMORPHIDAE. 



The genera belonging to this family that are sufficiently well known to be 

 generally recognised are Branchioceriantkus, Monocaulus, Corymorpha, Lampra, 

 Gfymnogonos, Seterostephanus. 



The genus Branchioceriant/tus (Mark 15 and 16) appears to be perfectly distinct, 

 and does not offer any difficulties to the systematist. Corymorpha (M. Sars, 1835) 

 and Ileterostepliauus (Allman) differ from the other genera in producing in both sexes 

 free medusiform gonophores. Allman (2 : pp. 395-6) introduced the genus Monocaulus 

 for the species with adelocodonic gonophores described by Sars as Corymorpha glaciati*, 

 and he included in the same genus Corymorpha pendula (Agassiz) and the giant 

 deep-sea species Monocaulus imperator. 



