Freshivater Algm of North Wales. By Wm. West. 287 
M. ^papillifera Breb. P., Do. 
A form of this was often seen from Llyn Padarn with cells always 
longer than broad. 
M. iruncata Corda. P., A., Do., S. 
A form of this species was seen from Llyn Padarn, which might 
be termed glanduliferous, as each tip of the divisions bears an apparent 
gland. Another peculiar variety of this species was seen with a 
gaping sinus and narrower isthmus. 
M. crenata Breb. Do., B. 
M, Jenneri Kalfs. D. 
var. SIMPLEX nov. var. Fig. 34. 
Yar. lobis quinque semicellulse leviter concavis et 
incisuris brevioribus. 
This chiefly differs from the type by having each of the five lobes 
of the semicell but slightly concave, and the incision not so deep. D. 
Genus Euastrum Ehrb. 
*E. verrucosum Ehrb. var. simplex Josh. A. 
Long. 65 //, ; lat. 60 fjb ; lat. apic. 27-30 [jl. 
E. ohlongum Grev. Do., S., D., B., P. 
E. crassum Ktz. D. 
A form of this was frequent, which had a marked protuberance 
about half-way up the side of the front view of each semicell. 
Fig. 33. 
E. pinnatum Kalfs. C. 
E. humerosum Kalfs. P. 
E. ventricosum Lund. D. 
This rare species was in great abundance in a gathering made by 
J. H. Lewis at Dolgelly. 
Long. 80-95 ; lat. 52-60 //. ; crass. 27-29 /x. 
E. affine Kalfs. C., B., Do., P. 
E. ampullaeeum Kalfs. P. 
E. insigne Hass. D., S. 
E. didelta Kalfs. S., P., Do., A., B., D. 
E. cuneatum Jenner. A., S., F., Llyn Idwal. 
E. ansatum (Ehrb.) Kalfs. S., P., B., D., Do., F. 
E. sinuosum Lenor. S., C. 
E. pectinatum Breb. P., A., D., B. 
E. elegans Breb. Do., S., P., A., F. 
var. hidentata Nag. C., P., B. 
*E. pseudelegans Turn. C. 
This had the five central markings confluent; it also had the 
