W. WEST AND (;. S. WEST; ALGA-FLORA Of YORKSHIRE. I07 



507. Staurastrum proboscideum Arch. 

 Mw W.— Cam Fell (viii. 1896). 



508. Staurastrum asperum Breb. 



N.W.— Mickle Fell. Mossdale Moor, 'Widdale Fell. 

 S.E. — Riccall Common. 



509. Staurastrum capitulum Br^b. 



Van amcenum (Hilse) Rabenh. [Syn. S. amanmm Hilse]. 



Mid W.-.01d Cote Moor. Cam Fell. 



N.VV.— Bog near Widdale Beck. 



AVe think there can be no question that S. amxnuiii Hilse is 

 referable to S. capitulum Bre'b. as a variety ; it appears to be a 

 more frequent and widely-distributed plant than typical S. 

 capUulum. 



Varieties of S. aipitu/uin are easily distinguished from varie- 

 ties of S. pileolatum by the lateral projection of the superior 

 angles of the semicells, and by the broader, flattened apex ; the 

 granulation of the cells is also much coarser. 



510. Staurastrum pileolatum Brdb. 

 N.W.— Mickle Fell. 



Var. Brasiliense (B6rg.) Liitkem. [Syn. S. amcenum var. 

 Brasiliense Borg. in Vidensk. Medd. f. d. naturh. 

 Foren. Kjobenhavn, 1890, p. 45, t. iv., f. 44; West 

 in Journ. Linn. Soc, Bot. vol. xxx , 1894, p. 179, 

 t. xxiii., f. 9.] 

 N.W.— Bog near Widdale Beck. 



We fully agree with Liitkemiiller in regarding S. amanum var. 

 Brasiliense as a variety of S. pileolatum Brdb., as its characters 

 are in every respect those of the latter species. The ring of veri u- 

 cations at the base of the semicells is by no means constant in 

 character, and the specimens observed were somewhat inter- 

 mediate between var. Brasiliense Liitkem. and var. cristatum 

 Liitkem. with regard to this feature. 



511. Staurastrum scabrum Breb, 

 N.W.— Lund's Fell (iv. 1898). 



