4 
Transactions of the Society. 
Genus Penium Breb. ; De Bary. 
P. inconspicuum sp. n. Figs. 6 and 7. 
P. minutissimum, 3-plo longius quam latius, cylindrico- 
fusiforme, ad apices subtruncatum, medio distincte sed leve et 
gradatim constrictum ; a vertice visum circulare ; membrana 
laevi et acbroa. 
Long. 15-17 ya ; lat 4 *8-5 *4 ya. 
Eab. Biccall Common, E. Yorks. ; Elter Water, Lake 
District. 
This is a very minute species of a characteristic shape. It 
occurred in abundance from the first-named locality. 
P. Clevei Lund. (Desm. Suec., p. 86, tab. 5, fig. 11). 
var. crassum var. n. Fig. 5. 
Yar. cellulis diametro 2-plo longioribus, lateribus con- 
vexioribus, ad utrumque polum granulis minoribus, 
pyrenoidibus singulis, magnis. 
Long. 80-98 ya ; lat. max. 42-43 ya ; lat. med. 39 * 5- 
40 ya. 
Eab. Bog, at side of Angle Tarn, Lake District (1500 
feet). 
P. cucurbitinum Biss, in Journ. Boy. Micr. Soc., 1884, p. 197, 
tab. 5, fig. 7. 
forma minor. 
Long. 50-58 ya ; lat. 22 • 5-25 ya. 
Eab. Craig-an-Lochan, Perthshire, Scotland. 
Genus Cylindrocystis Menegh. 
C. diplospora Lund. (Desm. Suec., p. 83, tab. 5, fig. 7) subsp. 
major West (Freshw. Alg. of W. Ireland, p. 131, pi. xx. 
%• 5 -) n 
forma constricta. Fig. 9. 
Forma cellulis leve constrictis, cylindrica vel polos versus 
levissime dilatata. 
Long. 109-112 ya; lat. 48-54 ya ; lat. isthm. 45-50 ya. 
Eab. Biccall Common, E. Yorks. 
Genus Euastrum Ehrnb. 
E. oblongum (Grev.) Ralfs, Brit. Desm., p. 80, tab. xii. 
var. cephalophorum var. n. 
Semicellulae incisuris subapicalibus linear ibus et inci- 
suris inferioribus latis rotund atisque. 
Long. 155 ya ; lat. 90 ya ; lat. isthm. 30 ya. 
Eab. Spittal of Glen Shee, Perthshire, Scotland. 
The E. oblongum figured by Wolle (Desm. U.S., pi. xxv. fig. 6) 
dently a form of this variety. 
