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 (VV. B. Turner). Pilmoor, near Thirsk. 



285. Micrasterias Americana (Ehrenb.) Ralfs. 



^TID W.— Askwith Moor (W. B. Russell and R. Hebble- 

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



N.W.— Mickle Fell. 



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

 t. 291, {. 13). 



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

 of isthmus, 19 /*. 



Genus XANTHIDIUM Ehrenb., 1834. 



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

 S.W.— Cullingworth. 



Mid W.— Adel. Ilkley (W. H. Dikes). 

 N.E. —Strensall (W. B. Turner). 



287. Xanthidium antilopseum {Bi6h.) Kiitz. 



[Syn. X. fasciciilatum var. polygonum Ehrenb.J. 

 Mid \V. — Wigton Moor. Bog two miles south of Clapham. 

 N.W.— Cronkley Fell. 



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

 zygospores, vi. 1898). 



288. Xanthidium cristatum Br^b., 1848. 

 N.W. —Cronkley Fell. 



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

 S,E. — Riccall Common, 



