Clare Island Survey — Fresh-water Algae. 16 25 



Fain. Pleurococcaceae. 

 Pleurococcus angulosus Menegh. — W. 



vulgaris Menegh. — C, L ; W, and on mainland everywhere. 

 Trochiscia reticularis (Eeinsch.) Hansg. — C. 



Farn. Hydrodyctyaceae. 

 Snb-fam. Pediastreae. 

 Pediastrum boryanum (Turp.) Menegh.— C, L, K, EL, I, LG, CI, VL, W, 

 DL, L, SL. 



var. PRODTJCTTJM var. nov. — Var. processibus cellularum 

 externarum perlongis, inulte longioribus quam latitudo 

 cellulae et non capitatis. C. 

 duplex Meyen. — VL, W ; D, average breadth of colonies of 16 cells 



56/*, of 8 cells 43/*. 

 tetras (Ehrenb.) Ealfs.— C, L, LG, CI, W, DL, D, Cr. Colonies of four 

 were mostly seen. In one gathering from Clare Island, all seen 

 were in fours, the colonies were very small and measured usually 

 9-10/t across, rarely 11/*; the notch was subliuear, and the two 

 outer sides of each cell were always retuse. 

 *glanduliferum Benn. — Plankton of EL, LG, VL, L. 

 *gracile A. Br. — VL, C. 



Fam. Protococcaceae. 



Sub-fam. Coelastreae. 



Sorastrum spinulosum Nag. — C ; plankton of LG. 



Coelastruni sphaericum Nag. — C, very frequent : I, L, CI ; W, diameters of 

 colonies 34-36/*, of cells 8"5-9/* ; VL. 

 eambrieum Arch. — C. 

 microporum Nag. — C. 



Sub-fam. Crucigenieae. 

 Crucigenia quadrata Morren. — C, VL. 



Tetrapedia (Kirchn.) W. & G S. West,— VL, C. 

 rectangularis (Nag.) Gay. — C, in several places, 4-4'5 x o'S-G'S/i. 

 *Tetrastrum staurogeniaeforme (Schrod.j Chodat. — VL, DL. 



Sub-fam. Selenastreae. 

 Scenedesmus antennatus Breb. — W. 



acutiformis Schroder. — C, W, DL, D, VL ; Cr, some of the forms from 



here were rather broad, 14 x 5'5*(. 

 bijugatus (Turp.) Kiitz.— C, I, LG, W; Cr, cells 10-11 x 4-5-5/*. 

 denticulatus Lagerh. — S.W. of D 



B.I.A. PROC, VOL. XXXI, D 16 



