116 



OOCYSTIS ANIJ EREMOSRH.ERA, 



wholly or partially converted into a mass of yellowish-red globules 

 closely surrounding the' nucleus. On the cell resuming its normal 

 existence, these are gradually transformed again into chloroplasts. 

 I have observed the occurrence of this reddish substance in 

 Oocystis ovcdis also, and in a swamp-form of 0. lacustris (see 

 notes under these species). The last remnants of it may be noted 

 as a faint, red tinge surrounding the central body. 



HypnoHpores. — In sample No. 149, 

 among quantities of Ereviosphn'ra- 

 cells of various shapes, I noted the 

 formation which is reproduced in Text 

 fig. 6. There was an outer cell( x 110/a) 

 whose cell-wall differed not at all from 

 that present in typical forms of Ere- 

 nt.osph(cra, and within, a smaller cell 

 ( X 90/^-) with two membranes, the 

 outer thin and smooth, the inner to 

 all appearance thick ( x 5 /a) and cer- 

 tainly coarsely scrobiculate. I am of 

 opinion, however, that the incrassate character of the inner mem- 

 brane was an optical illusion. All the membranes were hyaline. 

 The contents were shrunken, and details could not be discerned. 

 The inner sphere, at any rate, was tilled with a thick, mucila- 

 ginous substance, as, under pressure, the contents exuded. T am 

 tentatively putting this down as a hypnospore. 



Text-fig. t). — Hypnospuie of 

 E. riridix,( x 335). 



'.^.F ravioli sly published types. 



Of previously described species, such a large percentage has 

 been observed locally, that it was thought worth while to include, 

 within the scope of this paper, remarks on all f(jrms published to 

 date. Since De Toni's 8ylloge Algarum, Vol. i., Chlurojjhycea', 

 was brought out in 1<S<^9, a large number of species of greater or 

 less validity has gradually accumulated. These are scattered 

 through the pages of various scientific periodicals, and the papers 

 in which they are embodied are often very ditticult to obtain. Of 

 the latter, the most important is W. West's, New British Frw. 



