DOCIDIUM. 19 



I). FixXFOWll? Hal). A variety. Plate IX, rig. 5. 



Charge, about eight times longer than the larger diameter; 

 suture distinct ; solitary inflation at base of semi-cells ; Bides 

 straight, tapering slightly in straight lino from the centre to 

 thr broad truncate apex, each angle furnished with a prom- 

 inent tooth ; cytioderm firm, coarsely verrucose. 

 Diameter at I >:i~i- of semi-cell 68 ft.; at apes 50 ft. 



From pond on Mt. Everett, Massachusetts. A large, firm 

 ami distinct form; not identical with the described plant, but 

 it is tolerably near it. 



I). Baculuu (Breb.,) 1 >. By. Plate XI. figs. ".. I. 



blather long, cylindrical, straightish margins slightly taper- 

 ing toward- the ends, or nearly parallel ; apices truncate, 

 rounded. Cytioderm smooth anil colorless. 



Diameter 1 I 22 it. 



4 



In general form very near />. Trabeculum, hut smaller and 

 devoid of the terminal vacuol< 



Ponds, Pennsylvania, New Jersej and Florida. Bailey 

 found it also in Georgia. 



D. CORONATUM, Pah. Plate X I. figs. ''. 1". 



('ells stout, cylindrical, slightly tapering from middle to 

 end- ; suture projecting on each side ; semi-cells inflated at the 

 base and bordered by <>ne or two row- of tubercles at the apex, 

 which produce a crenulate appearance. 



A -mailer form ha- the -utiire imperfectly developed. 

 Vacuoles, with active granules, are usually large and distinct. 

 Diameter 22-56 u. 



Ponds, Pennsylvania, N \\ Jersey, Massachusetts. 



D. CORONDIjATUM, Grun. Plate LI I I, fig. 16. 



Smooth or finely punctate, subcylindrical, -lightly attenu- 

 ated near the ends ; apices truncate, ornate with a crown of 

 pearly teeth. Twelve time- as long as broad. 



Diameter in middle 38 ft. Near the ends :!.'! ft. 



The original form of this species was found in the East 

 Indies; the plant was somewhat thicker, but of about the 

 same proportionate length, and so near otherwise, I adopt 

 the name. Collected it in northern New Jersey ; found 



4 



