326 DR, Е. E. FRITSCH ON FRESHWATER ALG 
SCENEDESMACE.E (sensu Oltmanns). 
14. Oocysris LACUSTRIS, Chod. an Bull. Herb. Boissier, v. 1807, p. 296 & 
pl. 10. figs. 1-7, forma xivaLis, F. 17. Fritsch. (РІ. 10. figs. 27, 28.) 
Poli cellularum rotundati vel acuti : in cellula aliquantum adipis flavi. 
Long. cell. =13-15 ш; lat. cell. =9-10 р. 
Samples 1-3 (yellow snow !), rare. 
This form has been fully considered on p. 513. 
15. Oocvsris SOLITARIA, И». in Wittrock et Nordstedt, Alg. aque dule. 
ersice, по. 244, Bot, Notiser, 1819, р. 24 & fig. 
Sample 11, rare. 
Cells ellipsoidal in shape with rounded ends ; membrane moderately thick, 
with apparently two layers, slightly thieker at the two ends of the cell : cells 
generally solitary, but now and again to the number of about eight within a 
mother-cell. Fat generally present in the cell.contents ; length of e.lls 
=16-20 ш: width =13 y. 
16. CHODATELLA BREVISPINA, F. E. Fritsch. (Pl. 10. figs. 25, 26 ; PI. 11. 
phots. 3, 5.) 
Cellule. ellipsoideze. plus minusve complanatæ setis brevibus qua non 
amplius bis crassitudine membrane cellule exstant per totam superficiem 
externam confertz ; кеке plerumque tenues et angustee, interdum paulo 
crassiores, æquilongæ ; inter ea que cellula continet semper est adeps, 
plerumque abundans, хере similis duobus globis in utroque fine cellule. 
Long. cell. = 17-20 ш; lat. cell. —10-15 p. 
Differs from all hitherto described species of Chodatella in having very 
short spines, which cover the surface uniformly. 
Samples 1 and 8 (yellow snow !), common ; isolated in sample 10. 
А full consideration of this species will be found on pp. 311—313. 
ScoTIELLA, F. №. Fritsch. 
Cellulee ellipsoideze in utroque fine rotundatæ processibus alzeformibus plus 
minusve longitudinalibus sex aut multis munitz ; ale sunt aut rect: aut 
undulate ; chromatophoram singularem esse probabile est, cum pyrenoide ; 
abundantia est adipis in una specie.  Propagatio subdivisione cellule 
immutatee aut ѕроге perdurantis in paucas partes verisimile est. Spore 
perdurantes eum membranis valde incrassatis transfiguratione cellularum 
vulgarium formari videntur. 
This genus is certainly a close ally of Oocystis (ct. p. 907). I think it very 
probable that Pteromonas nivalis (Shuttlw.), Chodat, is а species of this 
genus (cf. p. 310). 
