DOCIDIUM. 25 



Found this species most frequent in smaller pools in 

 Florida. By specimens seen from Brazil, S. A., it is evident 

 that this form is liable to great variation in size, having 

 some as large as 125 fi diameter. 



C. DELPONTII, Klebs. (C. crassum, Delp.) Plate LV, fig. 9. 



Cells cylindrical, somewhat inflated in the middle, gradu- 

 ally tapering to an obtusely rounded apex ; distinctly striate 

 with one, two or three sutures about the middle ; cell twenty 

 times (more or less) longer than broad. 



Diameter 35-45 ^. 



Delponte's name of Crassum having been previously ap- 

 plied to another species by Rabenhorst, Klebs changed it. 



C. LINEATUM, var. COSTATUM, Wolle. (Comp. Des. U. S. p. 43.) 



Plate LXI, fig. 3. 



This variety differs from the usual form in having the 

 striae very thick and few in number. The figure represents 

 one of many fruiting specimens found by W. N. Hastings, 

 Rochester, New Hampshire. 



C. DIANAE. Plate LV, figs. 1, 2. 



Two specimens, differing particularly in size from those 

 represented in Des. TJ. S. Plate VII, figs. 8, 9. Not rare. 



C. PRONUM, Breb. Plate LV, fig. 22. V. Des. U. S. p. 46. 



Cells very small, sublanceolate, each end drawn out into a 

 setaceous beak about half as long as the body; cytioderm 

 finely striate. 



Diameter 7-12 /*. 

 Ponds, Florida. 



C. DIDYMOTOCUM, (V. Des. U. S. p. 39). Plate LV, fig. 10. 



A large form and distinct variety corresponding to de- 

 scription by Delponte. Cytioderm not longitudinally striate, 

 but smooth and apices obtusely rounded. 



Diameter 50-60 /<. 



Minnesota and New Jersey. 



Genus, DOCIDIUM. V. Des. U. S. p. 47. 



D. ARCHERII, Delp. Plate LIV, fig. 2. 



Cells smooth, cylindrical about twenty times longer than 

 broad ; scarcely attenuated from the middle to the ends ; 

 apices broadly rounded or truncate ; base of semi-cells with 



