476 



SUPPLEMENT. 



Fig. 86. 



jmiSk 



M. Sars reduces the Lucernaria quadricornis of Muller, and the 

 L. fascicularis of Fleming to one species, a conclusion at which Mr. 

 Alder had almost arrived. See p. 252. 



Sars doubts whether I am right in making the Luc. convolvulus, 

 Johns, synonymous with the Luc. campanulata, Lamour. ; and he 

 complains of the imperfection of my description of the species. This 

 I [regret that I cannot amend nor render more complete. The 

 species is liable to considerable variation. May there not be awant- 

 ing in M. Sars the faculty of apprehending the written characters of 

 a species 1 Some good naturalists are defective in this faculty, 

 and hence their constant reference to figures, and their inordinate 

 estimation of their value. 



POLYZOA INFUNDIBULATA. 



EUCBATIAD^. 

 HiPPOTHOA (p. 291) CASSITERIDES, Coucli. (Fig. 87.) 



" H. encrusting, calcareous ; cells ovoid., connected to each 

 other hy a short stout thread ; openings nearly round, with 

 thickened rims ; a short distance from the proximal lip is a 

 small pearly tubercle.'''' R. Q. Couch. 



Hab. " On a stone between the Scilly Islands and the Lands- End. 

 This species I found on a bit of stone dredged up off the Lands-End. 

 The number of perfect cells is six, with a few others partially de- 

 veloped. Their general appearance is that of //. lanceolata, but 

 under a lens, other characters appear which indicate a distinct 

 species. The cells are stouter and more pear-shaped, and the threads 

 of connection shorter and stouter, being about one-third the length, 



