Freshwater Algse of North Wales. By Wm. West. 293 
Long. 76-85 /x; lat. 55-65 /x; lat. isthm,, 25 /x ; spinarum 
long, ad angulos 11-15 /x. 
Frond rather large, one-third longer than broad, semi- 
cells broadly elliptical, end view triangular, with slightly convex 
sides, beset with spines except at the constricted part, many of 
which are much longer about the apices of the angles. C. 
var. CAMBRicuM nov. var. Fig. 6. 
Yar. semicellulis subangularibus et isthmo angustiori. 
Long. 83 ya ; lat. 60 fi ; lat. isth. 20 ya. 
This differs from the type by having the semicells somewhat 
angular, and the isthmus narrower. C. 
var. CAMBRICUM nov. var. forma minor. Fig. 37. C. 
Long. 62 ya ; lat. 48 ya ; lat. isthmi 13 ya. 
I first noticed this species in a gathering from Lindeth in West- 
moreland a few years since, and it has been named in a manuscript 
for some time. I have since noticed it in a gathering from Capel 
Curig along with its variety cambricum. It differs from St. 
Pringsheimii Eeinsch in its larger size, and in its relatively sharper 
spines of varying lengths. It differs from St. senticosum Delponte 
in being longer than broad, whereas the latter is broader than long, 
and also has its long spines more uniformly arranged. St. Notarisii 
Delponte differs in having its uniform spines regularly arranged as 
well as in its narrower sinus. St. saxonicum Buln. differs in 
its relatively broader isthmus and its shorter uniform spines. 
S. Pringsheimii Keinsch. P. 
S. Botjanum Arch. (S. setigerum Cleve). C. 
S. spongiosum Breb. B., P., Do. 
S. Griffithsianum (Nag.) Arch. C., Do. 
S. asperum Breb. C., F. 
S. saxonicum Keinsch. S. 
*S. coarctatum Breb. var. subcurtum Nord. C. Fig. 8. 
S. 7)iuticum Breb. B., S. 
S. o7'biculare Ealfs. A., B., F., P. 
S. osTEONUM nov. sp. Fig. 7. 
S. minutum, sinu latissimo et obtuso, semicellulis 
rotunda to-ellipticis, a vertice triangulare, angulis rotundatis 
et lateribus concavis. 
Long. 14 /X ; lat. 6 • 5 /x ; lat. isthmi 3 yix. 
Minute, front view shaped like a dumb-bell, end view 
trigonal with slightly concave sides, cytoderm smooth. C. 
S. pygmseum Breb. C., S., F„ Bodorgan. 
S. lanceolatmn Arch. C. 
S. inconspicuum Nord. C. 
This characteristic but rare species was often noticed, and it 
showed no variation. 
1890. 
X 
