MASSEE : MARINE ALG/E OF SCARBOROUGH. 



Porphyra laciniata Ag. ( = Porphyra laciniata Harv. ; Porphyra 



vulgaris Harv.) 

 Porphyra leucosticta Ag. 



North Ba)^; rare. This species differs from Porphy?a laciniata 

 in being brighter in colour, and the antheridia are in groups 

 within the margin, and not marginal. 

 Bangia fusco-purpurea Lyngb. 



On stones and woodwork of the South Pier. 

 Erythrotricha ceramicola Lyngb. 



On smaU algae in tide pools. Separated from Bangia on 

 account of the absence of antheridia and tetragonidia. 

 Peyssonelia dubyi Crouan. 



Forming a liver-coloured film on rocks. 

 Petrocelis cruenta Z. Ag. 



On rocks, North Bay. 

 Hildenbrandtia rosea Kutz. ( = Hildenbrandtia rubra Harv.) 



On smooth rocks, Carnelian Bay. 

 Callithamnion plumula Lyngb. 



North Bay ; rare. 

 Callithamnion pluma Ag. 



Not uncommon on Furcellaria and Laminaria. 

 Callithamnion tetragonum Ag. 



South Bay. 

 Callithamnion roseum Lyngb. 

 Callithamnion byssoideum Harv. 



In rock pools, South Bay. 

 Callithamnion polyspermum Ag. 

 Callithamnion rothii Lyngb. 



Forming a dense velvety pile on rocks and clay near low water. 

 We find the tetraspores cruciate, as described by Thuret, Nasgeh, 

 and Farlow ; Harvey describes them as being tripartite. 

 Griffithsia setacea Ag. 



South Bay. Rare. In this species the ' continuity of proto- 

 plasm ' was first observed. 

 Kalnrus eqnisetifolius (Ag.) Kutz. 



One specimen thrown up in the North Bay. Not uncommon 

 at Bridlington. 

 Ptilota plumosa Ag. 



Ptilota elegans Bonnem. ( = Ptilota sericea Kutz.) • 

 Ceraminm rubrum Ag. 



Ceramium rubrum Ag. var. proliferum Ag. ( = Ceramium botryo- 

 carpum Harv., Phyc. Brit., pi. 215). 



Naturalist, 



