THE HYDROIDS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 47 



St Vincent, Cape Verde Islands. 



EucopeUn crenata (1), Hartlaub. 



Sertularella fusiformis ('!), Hiiicks. 

 Lat. 27° 54' N., long. 33° 17' W. 



Clijtia Johnstoni (Alder). 



Sertularia mayeri, Nutting. 

 Station 537, 29° 54' N., 34° 10' W. 



Campanuhiria cJyfioides (Lamx.). 



Ohelia hyaliva, Clarke. 

 Station 538, 32° 11' N., 34° 10' W. 



PluTiiularia setacea (Ellis). 



Aglanphenia laiecarinata, Allnian. 



Myriothela austro-i/coiyiw, Jaderholm, 1904. 



Several specimens of this bizarre Hydroicl have to be recorded. All came from a 

 single neighl)ourliood, Scotia Bay in the South Orkneys, but the depths at which the 

 specimens were obtained varied. Some of the examples have already been described by 

 Professor J. Arthur Thomson in a short paper in which he regards them, not without 

 hesitation, as the separated gonostyles of some unknown giant Siphonopore (Thomson, 

 1904). There can be no doubt, however, that these specimens are identical with those 

 found by both the Swedish and the French Antarctic expeditions, and recorded by Drs 

 •Jaderholm and Billard (1906, p. 4) as Myriothela austro-georgm. The length, the 

 thickened basal portion on which the blastostyles (each bearing its male or 

 female gonophores and a distal tentacle or two) are massed, and, most characteristic 

 of all, the capitate tentacles scattered irregularly over the whole hydranth, even 

 amongst the blastostyles — these features show that our examples belong to the same 

 species as theirs. Nor can there be any doubt that Jaderholm was correct in regarding 

 his specimens as belonging to the genus Myriothela, for their resemblance to the 

 northern forms is striking, — solitary hydranths, absence of hydrocaulus, capitate 

 tentacles scattered over the body, blastostyles grouped at the base of the hydranth, the 

 presence of longitudinal folds of endoderm lining the inner cavity. 



Professor Thomson remarks that some of the colonies bore solitary gonophores, while 

 one had as many as seven on its blastostyles, and suggests the possibility of the presence 

 of two species. Since, however, the specimens examined by Jaderholm had generally 

 from one to three, but sometimes as many as six female gonophores, while the male 

 gonophores occasionally numbered even ten on a single blastostyle, the variation is so 

 great that little stress can be laid on this as a specific character. 



A water-colour sketch made on the capture of one of the specimens indicates that 

 their colour was a stronger and bi'ighter orange than is shown by Jaderholm's figure. 

 (Jaderholm, 1905, pi. i.). 



Locality. — Scotia Bay, South Orkneys ; dredged in 10 fathoms, April 1903 ; dredged 

 in 9 to 10 fathoms, May 1903 ; dredged among mud and pebbles, 18th December 1903. 



(ROT. see. EDIN. TRANS., VOL. XLVIL, 69.) 



