W. WEST AND G. S. WEST : ALGA-FLORA OF YORKSHIRE. 67 



Cocket Moss, near Giggleswick. Bowland Knotts. Bog two 

 miles south of Clapham. 



N.W.— Mickle Fell. Great Shunnor Fell. 



N.E. — Strensall ! (W. B. Turner). Seamer. Carlton Bank. 

 Stokesley. 



Var. notata Nordst. 



N. E. — Terrington. 



283. Micrasterias Thomasiana Arch. 

 Mid W.— Malham Tarn Bog (iii. 1894). 

 N.E. — Pilmoor, near Thirsk. Terrington. 



284. Micrasterias Crux-melitensis (Ehrenb.) Hass. 

 N.E. — Strensall (\V. B. Turner). Pilmoor, near Thirsk. 



285. Micrasterias Americana (Ehrenb.) Ralfs. 



Mid W.— Askwith Moor (VV. B. Russell and R. Hebble- 

 thwaite). Cocket Moss, near Giggleswick (iv. 1898). 



N.W.— Mickle Fell. 



Var. recta WoUe, forma. (Cfr. Journ. Bot., Oct. 1889, 

 t. 291, f. 13). 



N.W. — Mickle Fell. Length, 117 /x; breadth, 98 //,; breadth 

 of isthmus, 19 />i. 



Genus XANTHIDIUAI Ehrenb., 1834. 



286. Xanthidium armatum (Br^b.) Rabenh. 

 S.W. — CuUingworth. 



Mid W.— Add. Ilkley (W. H. Dikes). 

 N.E. —Strensall (W. B. Turner). 



287. Xanthidium antilopaeum (Brdb.) Kiitz. 



[Syn. X. fasciciilattim var. polygonum Ehrenb.]. 

 Mid W. — Wigton Moor. Bog two miles south of Clapham. 

 N.W.— Cronkley Fell. 



N.E. — Strensall ! (W. B. Turner). Pilmoor, near Thirsk (with 

 zygospores, vi. 1898). 



288. Xanthidium cristatum Brdb., 1848. 

 N.W.— Cronkley Fell. 



N.E. — Strensall ! (W. B. Turner). Pilmoor, near Thirsk. 

 S,E. — Riccall Common, 



