36 



V. On the Occurrence of a Supposed Australasian Hydroid 

 (Sertularia elongata) in the North Sea. By James 

 Ritchie, M.A., B.Sc, University of Aberdeen. [Plate 

 III.] 



(Read 28th January 1907.) 



In November 1904, Mr J. J. Simpson, M.A., B.Sc, while 

 searching for chance specimens in the nets of the trawlers 

 lying at Aberdeen Fish Market, came upon a magnificent 

 cluster of Hjdroid colonies, which he kindly handed to me 

 for identification. 



The colonies, of which there were about forty-five in the 

 bunch, are fixed upon a slender twig, 0'2 mm. in diameter 

 and 11 cm. in length, which is in many places encrusted by 

 Polyzoa. They vary considerably in size, the largest about 

 8 cm. in height and 15 cm. in breadth, the smallest about 

 2 cm. by 0'45 cm. When Mr Simpson found the specimens, 

 the coenosarc had already wholly disappeared. Both the 

 hydrocaulus and the gonothecse (which are numerous, 

 some of the colonies bearing a gouotheca on almost every 

 pinna) agree specifically with the descriptions and figures 

 of Sertularia elongata, Lamx., given by Prof. D'Arcy W. 



