40 TUFTS COI.I.KC.I: STI-UIKS, VOL. IV, No. 7 



A cut, however rude, gives a better idea of this species, than 

 a description, however full ; this is true more or less of all 

 species of the genus. To do any work in it one should have 

 either a library with everything published on fresh water algae, 

 or Pascher's handbook, with its cuts. 



28. T. HASTATUM (Rcinsch) Hansgirg, 1888, p. 132; Poly- 

 tdrinm tctracdricum var. hastatiun Reinsch, 1867, p. 77, H V, 

 fig. III. Cells tetraedral, about 23 /* wide, with 4 lateral sub- 

 concave surfaces ; angles gradually narrowed, each with a single 

 spine, shortly tridentate. Wis., G. M. Smith. /Europe. 



Var. PALATINUM (Schmidle) Lemmermann, 1904, p. 112; 

 r^lytdriutn hastatum var. palalinum Schmidle, 1900, p. 148, 

 PI. VI, figs. 4-5. Cells rounded, mostly telraedal, less com- 

 monly disciform, each angle drawn out into a long prolongation, 

 bifurcate at the tip. Wis., G. M. Smith. Europe. 



29. T. ARTHRODESMIFORMK var. LOBULATUM Wolos/ynska. 



1914, p. 203, PI. VI, fig. ii. Cells with two long straightish 

 sides, each with a long, somewhat spreading prolongation, end- 

 ing in 2 short acute lobes, the 2 short sides deeply incised, 

 leaving only a narrow isthmus; width 1632 /*, length with 

 spines up to 56/1. Wis. G. M. Smith. Europe. 



In the typical form, T. tetragonum forma arthr^dcmniforme 

 G. S. West, 1909, p. 245, PI. CCCXCYIII, fig. i. the apices of 

 the prolongations are simple. 



30. T. VICTORIAB Wolos/yriska, 1914, p. 203, I'l. VI. ligs. 1-4. 

 Cells 4-lobed, deeply emarginate, forming two subcruciform, 

 strongly twisted semi-cells; angles rounded, with a shoit 

 straight spine with blunted tip; cells 20-30 X 10-15^. \\ i^ . 

 G. M. Smith. Africa. 



The original material from Africa had cells with dimensions 

 as above; Smith's plants from Wisconsin measure 40-60 X 

 15-20 /*, but do not differ otherwise. 



Page 167, cancel all in regard to ELAKATOTifRix, and sul. 

 stitute, 



Cells cylindrical or fusiform, with one parietal chromatophore, 

 nearly covering the wall, with pyrenoid ; an extensive gelatin- 

 ous thallus, often branching and anastomosing, including many 

 cells, usually in longitudinal series ; asexual reproduction }>\ 

 transverse division. 



