\v. Wkst ANn <;. s. west: alca-fkora ok vokKSHlkiv log 



Mid W.— Bramhope (J. Abbott). Ilkley (W. H. Dikes). AVig- 

 ton Moor. Penyghent. 



N.E. — Gormire (VV. B. Turner). Pilmoor, near Thirsk. 

 S.E. — Riccall and Skipwith Commons, 



517. Arthrodesmus Incus (Breb.) Hass. 



S.W. — Greetland, near Halifax (with zygospores). CuUing- 

 worth. Keighley Moor. 



Mid W. — Adel Dam (W. B. Turner). Bride Cross, above 

 Farnley Moor. Malham Tain. Cocket Moss, near Giggleswick. 

 Bog two miles south of Clapham (with zygospores). Penyghent. 

 Near Buckden. 



N.W.— Cowgil! Wold Moss, Widdale Fell. Mickle Fell. 

 Lunds Fell. 



N.E. — Gormire (W. B. Turner). Strensall C'ommon. Pil- 

 moor, near Thirsk. Moorland stream, near Scarborough. 



Var. Ralfsii (A\'est & G. S. AVest). [Syn. A. Ralfsii West]. 



S.W. — CuUingworth. 



N.E. — Pilmoor, near Thirsk. 



S.E. — Riccall Common. 



518. Arthrodesmus bifidus Breb. var. truncatus West. 

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



Length, 10-12 /v.; breadth, \Q-W2\ir, breadth of isthmus, 



4 '5 \'" 



519. Arthrodesmus octocornis Ehrenb. 



[Syn. Xanthidium odocorne Ralfs]. 



Mid W^— Bramhope (W. B. Turner). Ilkley (W. H. Dikes). 

 Wigton Moor. Cocket Moss, near Giggleswick. Bog two miles 

 south of Clapham. 



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



Genus ONYCIIONEMA Wall., i860. 



520. Onychonema filiforme (Ehrenb.) Roy & Biss. 

 [Syn. Tessararthra filiforinis Ehrenb. ; Sphcerozosma 

 fiUformis (Ehrenb.), Rabenh.]. 



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

 S.E. — Skipwith Common. 



