FRI.-IIWA ir.i: AJLQJI Of THB 80UTB OKKNKYS. |o-.i 



individuals HO l>;i<l in moat cases, that only a \<r\<-\ d-v-Tipii ..... -an I..- -ji\ .-n. Tin- .-.-IN 

 are oval, and of <-..n-id'ral>ly smaller dini.-n-ii>ns ili.m tlmso of S. antarctica ; in plan- 

 of the six wings of tin- latter the cells are provided with numerous longitudinal wings, 

 which vrenerally have a somewhat spiral trend (fig. 18, and eajx-eially figs. 19 and 21). 

 The wings do not stand off from the body of the cell nearly as prominently as in 

 S. n -i (cf. especially fig. 20, which is an oblique end-view of the organism). 



i of the wings is undulated (fig. 18), and this fact, together with the large number 

 of the wings, makes the cells present a notched crenate outline from whatever point 

 they are viewed (cf. figs. 20, 21). At the two ends of the cells the wings bend inwards, 

 and terminate in a shallow sinus (fig. 20, also 21 and 18). The wings are solid, as 

 in the other species, and appear as flat crenations in optical section (fig. 20). As 

 regards the contents of the cells of S. polyptera, in the few cases in which they could 

 be made out at all there appeared to be a single chloroplast with a prominent pyrenoid 

 (fig. 21); fat was not observed in the cell-contents of this species. Only one case of 

 possible reproduction was found (fig. 19); a cell of S. polyptera, in which the outline 

 of the wings had become obscure (visible, however, as delicate spiral lines in the right- 

 hand portion of fig. 19), contained a number of elongated protoplasmic masses, in one 

 of which a pyrenoid was prominent. This stage is possibly to 1..- int> rpreted as 

 division of the contents of the individual to form n number of daughter-individuals ; 

 if this is so, it of course constitutes a marked analogy to the probable stage of 

 S. antarctica shown in fig. 17. It may be added that the individuals of S. polyptera 

 were not uncommonly found in groups of four or five, which would quite accord with 

 their being formed by subdivision of a mother-individual. 



S. polyptera is obviously of a more dubious character than S. antarctica. While 

 some doubt may justly be felt as to its independence (for it might be the zygospore 

 of some form ? '), it is impossible to feel quite certain of its close affinity to 5. antarctica, 

 and further observations may warrant its removal from the genus Scotiella. In view 

 of the bad definition of the wings in all the cells observed, I am inclined to think 

 that no normal individuals of .S'. polyptera were present in ray material, and that 

 all the forms observed were either preparing for division or passing over into some 

 rcsting-stage.* 



(e) PTKROMONAS NIVALIS, Chod. (PI. I., figs. 22-24, 31). 



Another form, of which, however, only very occasional specimens were met with in 

 the yellow snow material, is represented in figs. 22-24 and 31 of PI. I. This is almost 



1 I hare not, however, met with anything to countenance thu view. Lagcrheim (" Schneeflora de* Pichincha," 

 Btr. Daittck. Rot. Get., x., 1882, p. 529 ; alo "Schneeflora in Lulea Lappmark,* Bat. CuUnML, iri., No. II, 1883) 

 relen to oral cell* (15 M broad and 30? long) as occurring in red mow from Anuterdanio (Spitsbergen). Theae 

 cell* are described M having longitudinal ridges, and may possibly represent the same form as X. polgpUra, or a 

 closely allied one. Lagerheun, however, regards these cells M probably being lygospores of Cklamfdomonat laUritia 

 (/. p. Ill, footnote IX 



1 AdiagnoMofS(oMfhjnlg<TgmBonp. 125. 



