8o YORKSHIRE NATURALISTS* UNION. 



Euastrum Pokornyanum, unconsciously confirms the view that 

 the two species are identical. 



As E. Pokornyanum was described four years previous to 

 E. bhuxh var. angustatuni, the specific name 'Pokornyanum^ 

 must take precedence. 



361. Cosmarium cymatopleurum Nordst. 1872. 

 Mid W. — Penyghent, extremely rare along with Staurastritm 



acarides, Cosnianujn Etchachanense, C. speciosum, C. anceps, etc. 

 Var. tyrolicum Nordst., 1876. 



[Syn. C. subochthodes Schmidle, 1895, pro parte.]. 

 Mid W. — Shipley Glen, forming pure gelatinous masses on 

 wet shaly rocks. Penyghent. 

 N.W.— Lund's Fell. 

 Var. Archerii (Roy & Biss.) Nob. 



[Syn. C. Archerii Roy &: Biss, 1893]. 

 Mid W. — Penyghent. 



Length, 91 /* ; breadth, 67 ft. ; breadth of isthmus, 24 /x.. 



The drawn-out apices of the semi-cells of this variety give it a 

 rather remarkable character, but this feature is not sufficient to 

 warrant its separation by Messrs. Roy and Bissett as a distinct 

 species. The specimens observed from West Yorkshire were 

 intermediate between the typical form and the var. Archerii with 

 regard to the produced apices ; they were also intermediate in 

 size, thus proving that these plants are forms of one species. 



This species and its varieties are essentially alpine Desmids. 



362. Cosmarium Holmiense Lund. 

 S.W.— Ogden Clough. 



Mid W. — Baildon. Holden Ghyll, near Keighley. Near 

 Ilkley. Cowside Beck, Arncliffe. Moughton Fell. Heseltine 

 Ghyll. 



N.W.— Mickle Fell. Lund's Fell. Cowgill \Vold Moss, Wid- 

 dale Fell. 



Var. integrum Lund. 



Mid W. — -Malham Tarn. Bog two miles south of Clapham. 

 Cowside Beck, Arncliffe. Penyghent. 



Trans. Y.N.U., 1897 (pub. Dec 1900). Bot. Series, Vol. 5. 



