76 TUFTS COLLEGE STUDIES, VOL. IV, No. 7 



CHLOROSARCINA Gerneck, 1907, p. 221. 



Cells solitary or united in colonies, with or without gelatinous 

 coating ; chromatophore parietal, with or without pyrenoid ; 

 product starch and oil ; asexual reproduction by division in 2-3 

 directions and by biciliate zoospores. 



KKY TO THE SPKCIKS OF CHI.OROSARCINA. 



i. Cell* without gelatinous coating. i. C. lacustris. 



i. Cells with gelatinous coating. 2. C.f>arrnl<i. 



1. C. LACUSTRIS (Snow) Lemmermanu in Pascher, 1915, p. 

 48; Chlorosphacra lacustris Snow, 1903, p, 386, PI. IV, fig. 14. 

 Cells spherical, ovoid or somewhat angular, 9-10.5 p. diain., 

 forming dense, at first flat, later spherical free colonies without 

 gelatinous coating ; pyrenoid present ; zoospores 4 in a cell, 

 narrowly ovoid, 6.5-9 X 2.6-4 /*, with stigma. Fig. 24. Lake 

 Erie, Snow. 



2. C. PARVULA (Snow) Lemmermann in Pascher, 1915, p. 

 48; CMorosfihaera parvula Snow, 1903, p. 386, PI. IV, fig. 15. 

 Cells spherical or ovoid, 7.8-9 /* diain., wall thin ; 4-8 united into 

 a flat, free gelatinous family ; pyrenoid present ; zoospores 4-8 

 in a cell, broadly ovoid or spherical, 5-6 /* diam., with stigma. 

 Lake Erie, Snow. 



The value of this genus, and the inclusion in it of these two 

 species, are very uncertain matters. The paper by Gerneck, in 

 which the genus is proposed, though undoubtedly representing 

 careful study, from a systematic point of view holds the record 

 for being everything that such a paper should not be. Leinnu i 

 maun transferred to the genus these two American species \\itli- 

 out having seen them, alive or dead. 



Page 309, after the description of GLOEOCYSTIS SCOPULORUM, 

 add, 



GLOHOCYSTOPSIS G. M . Smith, 1916, p. 474. 



Cells elongate-cylindrical, more or less curved, with rounded 

 ends, aggregated by 4 or 8 within a non-lamellated, sharply 

 defined, spherical, gelatinous sheath. Colonies of an indefinite 

 number of these aggregates arranged in a spherical or ovoid 

 mass ; chromatophore parietal, with one pyrenoid, later becom- 

 ing diffuse ; reproduction, aside from cell division, unknown. 

 Only species. 



G. LIMNBTICUS G. M. Smith, 1916, p. 475, PI. XXIV, fig. 12. 

 Cells 10-15 X 4-6 ft. aggregates 25-30/1 diam. ; colonies up to 

 i25Mdiam. Fig. 25. Wis., G. M. Smith ; Mass., F. D. Lambert. 



