KKKSIINV \IT.I: AIX>. OK NIK s<>i in MUKMY- 103 



description^' by tin- tlnillus i-.ni-i>iinu r "f a central group of irregularly arranged cell* 

 from which short filaments radiate out at the periphery. Of this feature I'rotoderma 

 Imnmii shows not Inn-, the edge of the thallus in all cases present iii'_ r jn>t a.s irregular 

 an .iiT.iip_ r --ni.-iit f the rolls as obtains in the middle /'. /'.,..../ also differs from the 

 other species of the genus in not being an epiphyte (cf. however p. 1-7). Rabenhorst's* 

 figure and description of /'. nr'nlf, Km/.., however, give no indication of any regular 

 arrangement of the cells, ami th- same is true of Migula's recent description, which 

 even refers to the cells as being " ordiiiingslos" and " nicht in Reihen." 1 The hitter's 

 liptimi of /Yi'Wfrmaalso recalls the Antarctic form, in that he speaks of the tlwllus 

 as "schlein This character is also referred to in Hansgirg'a description,* which 



further contains a statement (on p. '22b) as to the occurrence of oil drops in the cells. 

 It will therefor.- lie evident that all the characteristic features of /'. Ininntii have already 

 been referred to in the descriptions of /'. riridr, and it may ultimately prove to be but 

 a form of the latter. For the present, however, it seems U-st to keep it as a distinct 

 species, characterised by the irregular arrangement of the cells, the mucilaginous and 

 granular character of the walls, and the frequent presence of fat in the cell-contents.* 



(h) CHLORO.sriI.KRA ANTARCTICA, II. p. (1M. I., Jigs. 'J o ; PI. II., phots. I, 3, 5, 6, (7). 



The next most abundant form is a new species of Chlorosphstra, which may be 

 called C. antarctica, n. sp. (PI. I., figs. 2-6). This is found either in the form of large 

 isolated cell (figs. 2, 6) or as groups of smaller cells, commonly in fours or sometimes 

 larger numbers (PI. I., fig. 3) ; the average diameter of the cells varies between 1 1 and 

 26 M, although smaller and much larger cells were also observed. The cells are provided 

 with a well defined rather thick membrane, which, especially in the case of the isolated 

 cells, is often surrounded by a wide spherical sheath of transparent mucilage (PI. II., 

 phots. 1, 3), to the outer edge of which numerous small foreign particles were generally 

 adhering (PI. I., fig. 2). The isolated cells were mostly more or less spherical in shape, 

 while those forming groups were somewhat angular, probably as a result of mutual 

 pressure. In many cases an almost spherical chloroplast could be made out in the cells 

 without much difficulty ; this chloroplast is only interrupted on one side of the cell by a 

 small circular aperture, through which a small round body (in all probability the pyrenoid) 

 can be seen (PI. I., fig. 2). Starch is mostly present in small quantities in the smaller cells, 

 but is often scarcely to be found in the larger ones. On the other hand, large masses 



1 O. 8. West, The BritiA FrctHvater Algr, Cambridge, 1904, p. 204, and fig. 83 A-C ; N. Wille, "Conjugate and 

 Chlorophyewc," in Engler and Prantl, LHe natiirl. P/fcuum/bmttoii, Nachtr. z. 1 Teil, 9 Abteil. (Leipzig, 1909), p. 86 ; 

 cf. abo Hansgirg, Pndromtu d. AlymJIora r. Bukmcn, L (Prague, 1886), p. 28. 



* L. Rabenhorat, Flora europme algarmm aqua duleii * mbmantut. Hi,, Lipsur, 1868, pp. 288 and 907. 



1 W. Mignla, Kryptog-tnunJIara mm DnUidiland, ZtabdUWrndk *nd der &*NU, IL, 1 Teil, Ctoa, 1907, p. 747 ; 

 cf. also Wille, loe. ciL, 1 Teil, 2 Abteil., 1897, p. 78. 



4 " Meirt chliipferig," according to Hanagirg, loe. eit., p. 224. 



* A full diagnosis of Protodtrma frroimtt will be found on p. 126. It Mems rery probable that the form thown by 

 Wittrock (" Om snoni och Uea Flora," loe. eit.) in hi* fig. 1 7 (pi. iii.) belong! to thi* tpeciea, although the celU are more 

 regnUrly arranged than in my form. 



