734 
Transactions of the Society. 
Order Pediastre.e. 
Genus Pediastrum Meyen. 
P. angulosum (Ehrnb.) Menegh. B., Bn., Crummock Water. 
P. Boryanum (Turp.) Menegh. Frequent. 
var. granulatum (Kiitz.) A. Br. W., Bn., B., near 
Cockermouth. 
P. duplex Meyen (P. pertusum Kiitz.) B., Bn. 
P. Tetras (Ehrnb.) Balfs. Bn. 
*P. tricornutum Borge (Chloroph. fran Norska Finmarken, 
p. 4, f. 3). W. 
P. integrum Nag. Bn., L. 
Order Sorastreas. 
Genus Selenastrum Beinsch. 
*S. acuminatum Lagerh. in Wittr. et Nordst., Alg. exsic., fasc. 9, 
No. 441 ; Bidrag till kann. om Stockholms Pediast., Protococc., och 
Palmell., p. 71, t. iii. f. 27-30. Bn. 
S. obesum sp. n. Figs. 50-52. 
S. cellulis ohesis arcuatissimis, apicibus obtusis subacu- 
tisve; familiis e cellulis 4-8 constitutis, facile dissociatis ; 
apicibus cellularum adultarum 1 * 5-2 /z inter se distantibus ; 
contentum cellularum laete viride, granulatum. 
Crass, cell. 3-4*2 /z; diam. max. 6-9 /z. Bn. 
The form of the cells of this species at once distinguishes it from 
any other, the cells being bent until their a} dees almost meet. This 
sometimes occurred in masses containing from 4 to 21 groups, each 
consisting of 4-8 cells. 
Genus Sorastrum Kiitz. 
S. spinulosum (Kiitz.) Nag. Bn., Crummock Water. 
Genus Staurogenia Kiitz. 
S. rectangularis (Nag.) A. Br. Kirk Fell, Brandreth. 
Genus Coelastrum Nag. 
C. sphsericum Nag. Fig. 64. Bn., B., Hk., L. 
G. cambricum Arch. Bn., C. 
C. cubicum Nag. Bn. 
C. microporum Nag. B. 
PBOTOPHYTA. 
Group SchizophycEjE. 
Class Protococcoide^i. 
Order Eremobie^. 
Genus Hormospora Breb. 
*H. plena Breb. (Rabli. FI. Eur. Alg., p. 48). Bn. 
