220 Proceedings of the Royal Physical Society. 



GYMNOBLASTEA. 

 Eudendrium ramosum (Linn.). 

 Several colonies from Flamborough Head, Yorkshire. 



CALYPTOBLASTEA. 



Halecium beanii, Johnston. 



A single colony growing amongst the rhizoids of a clump of Plumularia 

 pinnata, dredged to the north of the west part of the Dogger Bank, North Sea. 



Halecium halecinum (Linn.). 

 Great Fisher Bank, North Sea. m 



Halecium muricatum (Ell. & Sol.). 



Typical colonies all bearing the characteristic gonaugia from — (a) deep 

 water to the north of the Dogger Bank, and (b) the south-east part of the 

 Dogger Bank, 18 fathoms. 



Campanularia volubilis (Linn.). 



A few steins, with hydrothecae, scattered over the trophosome of 

 Selaffinopsis hartlaubi, from the neighbourhood of Iceland. 



Lafoea dumosa (Fleming). 

 A few hydrothecte on the stems of Plumularia pinnata, from the uorth of 

 the west part of the Dogger Bank, North Sea. 



Grammaria abietina, M. Sars. 

 Two typical colonies from the neighbourhood of Iceland. 



Diphasia fallax (Johnston). 

 Great Fisher Bank, North Sea. 



Diphasia rosacea (Linn.). 



Two small colonies on Sclaginopsis hartlaubi, from the neighbourhood of 

 Iceland. 



Selaginopsis hartlaubi, Nutting. 



This species, till now known only from an incomplete specimen and a 

 fragment, is here represented by two colonies, one of which, however, is young 

 and incomplete. The complete colony (Fig. 1) is 22 cms. high and consists 

 of a stem, for the greater part denuded of hydroclades, divided into nodes by 

 well-marked internodes. The basal nodes (six or so) are irregular in size, are 



