W. West and g. s. west : alga-floea of Yorkshire. 15^ 



Mid W. — Forming bright green subgelatinous patches, along 

 with Cosmarium speciosum var. biforme, on constantly wet rocks, 

 Cowside Beck, Arncliffe. Diam. cell i ;«.. 



This species has not previously been recorded for the British 

 Isles. 



Genus SYNECHOCOCCUS Nag. 



761. Synechococcus major Schroter. 



[Syn. S. crassus Arch.]. 

 S.W.— Ogden Clough. 



Mid W. — Adel Bog. South of Cray Moss. Cowside Beck, 

 Arncliffe. 



N.E. — Pilmoor, near Thirsk. 



762. Synechococcus seruginosus Nag. 



Mid W. — Cowside Beck, Arncliffe. Langcliffe, near Settle. 

 N.W.— Mossdale Moor, Widdale Fell. 

 N.E. — Pilmoor, near Thirsk. 



Genus DACTYLOCOCCOPSIS Hansg. 



763. Dactylococcopsis montana West & G. S. West. 

 Cells solitary or associated in families of about 4 to 16; cells 



elliptical, barrel-shaped or oblique, with attenuated poles which 

 are slightly rounded at apex, about two to three times longer 

 than the diameter ; cells of the families generally somewhat dis- 

 tant from each other, after division approximate ; cytioplasm pale 

 Eerugineous. Length of cells, 8'6 — \v<^\i; breadth of cells 



3'S— 4^- 



The form of the cells readily distinguishes this species from 

 D. rupestris Hansg. and D. rhaphidioides Hansg. It also has a 

 different habitat, and the families of cells, which appear to be 

 surrounded by a small amount of mucus, attain a somewhat 

 larger size than in either of the two species mentioned. The 

 cell-walls are very firm and the division of the cells is in one 

 direction only, being somewhat oblique (as in DadylococcusS). 

 The chromatophore does not entirely fill the cell, there being a 

 clear space near to one margin (also as in Dactylococcus^); there 



