PLATE CXIX. 



FIGS. P AGE 



1. Staurastrum muticum Breb. forma minor 



Eabenli. x 520 . . .135 



2. St. minutifisimum Eeinsch. x 1250 (after 



Eeinsch) . . . .130 



3. St. minutissimum var. convexum W. & Gr. S. 



West, x 1250 (after Eeinsch) . . 131 



4. St. minutissimum var. convevum forma [= forma 



tetragonaNordst.']. x 570 (after Nordstedt) 131 

 5. St. minuiissimuinv&Y. convexum forma [ "forma 



trigona minor ' Wille]. x 400 (after Wille). 



Fig. 5 a represents two cells resulting from 



division; they are in a slightly oblique position. 



Fig. 5 a' is also in an oblique position . 131 



6. St. minutisaimumvsar. constrictum West, x 625 132 

 7. St. elliptic /an West, x 520 . .138 



8. St. coarctatum Breb. x 420 (after Brebisson). 



Front view only . . . 139 



9-10. St. coarctatum var. subcurtum Nordst. 9, x 400 



(after Nordstedt) ; 10, smaller form, x 400 . 139 

 11-13. St. grandeRulnh. ' x 520 . . . 140 



