722 
Transactions of the Society. 
G-enus Micrasterias Ag. 
M. mucvonata (Dixon) Rabh. Bo., Sk., Kirk Fell, Grisedale 
Tarn. 
M. Crux-Melitensis (Ehrnb.) Balfs. f. punctulata. 
Forma membrana irregulariter punctulata (subgrannlosa). 
Bn. 
The punctulations cause the margin of this form to appear 
minutely papillate. 
M. Americana (Ehrnb.) Ralfs. Deepdale. 
M. angulosa Hantzsch. G. 
Hi. denticulata Breb. Frequent. 
*var. angustosinuata Gay (Essai d’une monograph, des 
Conjug., p. 52, pi. i. fig. 4). L. 
var. subnotata var. n. Fig. 5. 
Semicellulae a yertice visas cum elevatione mediana 
latissime conica, lobi polari medio dentibus duobus 
parvis. 
Lat. 170 fi\ crass. 50 g. Bn. 
Compare with M. denticulata var. notata Nordst. (Freshw. 
Alg. of New Zeal, and Austr., p. 29, t. 2, f. 13). 
M. rotata (Grev.) Balfs. Bo., B., S., C., H. (at 2400 ft.), 
Deepdale. 
M. Thomasiana Arch. C. 
M. radiosa Ralfs. Bn. 
M. apiculata (Ehrnb.) Menegh. subsp. fimbriata (Ralfs) Nordst. 
Bn. 
M. papillifera Breb. Bo., Hk. 
; M. truncata (Corda) Breb. Frequent, 
forma punctata West. Bo., C. 
forma granulata Racib. Hk. 
M. Jenneri Ralfs. Sk. 
var. simplex West. ( M . Jenneri f. brasiliensis Boerg.) 
Sk. 
Genus Euastrum Ehrnb. 
E. verrucosum Ehrnb. B., W., S., R., Hk. 
E. oblongum (Grev.) Ralfs. Frequent. 
E. crassum (Breb.) Kiitz. W., C., Kirk Fell. 
E. ventricosum Lund. Hk. 
E . pinnatum Ralfs. Hk. 
E. humerosum Ralfs. Bt. 
E. affine Ralfs. Bt., B., C., Scawfell, Brandreth, Kirk Fell, 
Black Sail Pass. 
E. ampullaceum Ralfs. Bt., Hk., Brandreth, Kirk Fell, Black 
Sail Pass. 
E. insigne Hass. Frequent. 
