334 Mr George Traill on the 



220. Laurencia hybrida (De Cand.), Lenorm. {Laurcncia ccespUosa, 



Laiaour.) 



Common on exposed rocks and in pools at about half-tide level. 

 Rarely epiphytic on Alga;. All the year. Tetraspores in winter 

 and spring; ceramidia in July. 



221. Laurencia obtusa (Huds.), Lamour. 



Epiphytic on several of the smaller Algse between tide marks. 

 Annuah Summer. 



CHONDRIA, Ag. 



222. Ch-ondria dasyphylla (Wood.), Ag. {Laurencia dasyphrjlla, Grev.) 



On stones and shells in pools near low-water mark. Annual. 

 Hummer. Rare. On Dr Greville's authority. 



DASYA, Ag. 

 223. Dasya coccinea (Huds.), Ag. 



Fine and common in bays at the depth of from 4 to 10 fathoms. 

 Annual. April to October, Fruit in July and August. 



223a. Dasya coccinea (Huds.), Ag., var. tenuis, J. Ag. 



Scapa, fine ; Shapansey fine. Dredged in Kirkwall Bay by Mr 

 PoUexfen. Dr Asardh, to whom I forwarded specimens of this 

 plant in 1886, calls it var. tenuis, and says that it is probably a 

 northern form of Dasya coccinea. Mr Pollexfen writes to me in 

 regard to it as follows : — " I am inclined to think that the slender 

 variety of Dasija coccinea which I dredged in Kirkwall Bay, and 

 which you found at Scapa and Shapansey, is the D. coccinea, var. 

 y8 tenuior, described by Harvey in both editions of his Maiiual 

 of British Algse, but not mentioned in his Phi/cologia Britannica. 

 It was that which you sent to Agardh, and which he calls ' var. 

 tenuis.' The specimen in my collection named D. media was not 

 sent to him, and Mr Batters considers it quite distinct from the 

 other — indeed to be a new species. The latter I therefore place 

 as an addition to the Orkney list under the name Dasija media, 

 Harv, It was dredged by me in Kirkwall Bay, but not with the 

 other." 



224. Dasya media, Harv. 



Dredged by Mr Pollexfen in Kirkwall Bay, and probably a new 

 species. See Mr PoUexfen's remarks on the variety last mentioned. 



225. Dasya arbuscula (Dillw. ), Ag. 



Dredged in Kirkwall Bay by Mr Pollexfen. Identified by ISfr 

 Batters. Orkney is said to have been the original locality for this 

 species. 



