136 OOCYSTIS AND EREMOSPH^RA, 



medio 29/t; lat. max. 32'5/x." Considering the variation in 

 dimensions, which is general in these forms, this might very well 

 be included in the type along with that given above. Chodat 

 considers that this species is biologically a form of Eremosphcera 

 viridis, and with this I entirely agree. It is, however, a character 

 which 0. pand'urifotinis shares with all the other "species" of 

 Oocyst is. 



A var. pachyderma West, I.e., p-16, PI. ii., f.36, is also re- 

 corded, differing only in the very thick cell-wall ("membrana 

 cellularum 2 •5-2 "8 /x ci*assa," West. 



OocYSTis ovALis (Turner) W. k G. S. West. (PI. viii., f.l5, 16). 



"Mediocris, 2-2i-plo longiorquam lata; cellulis ovalibus, lateri- 

 bus ventricosis, apicibus rotundatis. Membrana crassa, glabra." 

 Turner, Ix. 



Cell. veg. 50 x 26, 62 x 32/x. 

 Rookwood(107). 



Syn., Cylindrocysfis ovalis Turner, Frw. Alg. E. Ind., 1892, 

 p. 16, T. i., f.5 (fig. sinistr.). About this form, W. 6: G. S. West, 

 .Some recently published Desmidiete, Journ. Bot., 1895, No. 387, 

 p. 6 6, remark: "From the perfectly elliptical form and smooth, 

 thick membrane, this appears to us to be a 

 species of Oocystis." Their opinion is con- 

 firmed by my finding it here in the form of 

 autospores, PI. viii., f.17. It is not surprising, 

 however, that Turner should have considered 

 Text fiff *>.3 ^^ ^ Cyfindrocystis, as the generally prevailing 



Cylindro€yxtii< ora/i.s character of the chloroplasts is unlike that of 

 Turner; after any other species of Oocystis, and, in some 



Turner. specimens, the contents are disposed almost 



exactly as in that genus, PI. viii., f.l5. The chloroplasts are 

 minute, fusiform or digitate masses, disposed longitudinally, and 

 radiating somewhat from the nucleus to the apices. The same 

 type of chloroplast is found also in Eremosphcera occasionally. 

 Turner's specimens were smaller than ours; he gives long. 40-42, 

 lat. 17-20/x. 



