COSMAPvIOI. 71 



92. Cosmarium sphagnicolum West & G. S. West. 



(PI. LXXI, figs. 11-14.) 



Cosmariv.m sphagnicolum "West & Gr. S. West, Alg. S. England, 1897, p. 

 486, t. 6, f. 13, 14; Obs. on Conj. 1898, p. 52, t. 4, f. 34-36; Alga-ti. 

 Yorks. 1900, p. 91 ; Alg. X. Ireland, 1902, p. 34; Notes Alg. Ill, 1903, 

 p. 10 (sep.) ; FresliAv. Alg. Orkneys and Shetlands, 1905, p. -'2. 



Cells minute, about as long as broad or a little 

 broader, moderately constricted, sinus short and open ; 

 semicells subtrapeziform, sides straight and divergent 

 upwards, lower angles obtuse, upper angles obliquely 

 truncate, apex broad, straight or very slightly retuse, 

 within each truncate upper angle furnished with a 

 minute papilla. Side view of semicell subcircular. 

 Vertical view elliptic, poles bluntly pointed,- ratio of 

 axes about 1 : 2, with a minute papilla on each side 

 near the poles. Cell-wall smooth. Chloroplasts axile. 

 one in each semicell, each with a single pyrenoid. 



Zygospore unknown. 



Length 10'5-11'5/x; breadth 11-13'5/x; breadth 

 of isthmus 5-5*5 ; thickness 6*0/1. 



Ex<iLAXP.--Cocket Moss, near Giggleswick, and 

 Mossdale Moor, Widdale Fell, W. Yorks ! Mickle Fell, 

 K". Yorks ! Thursley Common, Surrey 



WALES. Llvn Bochlwvd, Llvn Teyrn on Snowdon, 



t.' t/ *j ti 



and Y^ Foel Fras, Carnarvonshire ! 



SCOTLAXD.- -Finstown, Orkneys ! 



lEELAXD.--Xear Glenties and near Gweedore, 

 Donegal ! Louo'h Fea, Londonderry ! 



o o 



This minute species sometimes occurs in immense quantity 

 amongst Spliagnum in small, peaty pools, associated with 

 C. Cucurbtta. It is most nearly related to C. pygm&um Arch., 

 a species which often occurs in equal abundance in similar 

 situations. In the vertical view C. sphagnicolum and C 

 pygmienm cannot be distinguished from each other, but the 

 former is much less deeply constricted than the latter, and 

 its semicells are of a different form. We have never found 

 these two species intermingled, but as they occur in great 

 abundance in similar situations we consider them as very 

 closely related; perhaps they should be regarded as estab- 

 lished forms of one species. 



