119 



without the crown, it appears more nearly related to St. 

 ankjroides. 



Cosmarium sejunctum, n. sp. 



Membrane smooth, slightly longer than broad ; semicells 

 semicircular, with angles rounded, separated by a wide, 

 nearly linear sinus; isthmus narrow, less than one-fourth 

 the diameter of the cells. Diameter 20—25 /i. 



Ocean Beach, etc., N. J, 



Micrasterias dichotoma, n. sp. 



Semicells three-lobed; lateral lobes twice bifid; the ulti- 

 mate lobules (four resulting from one), deeply furcate or 

 clawed at their apices ; the polar, or end lobe, exscrted, on 

 a cylindrical neck, with two diverging arms, clawed at the 



ends. Diameter 175 — 200 ^. 



Ponds, Malaga, N. J., Harvey Lake, Penn. 



S. aspinosum, n. sp. 



Semicells smooth, in front view oval with end protrac- 

 ted into a colorless arm, about three times as long as the 

 breadth of the body, diverging; apices tricuspidate, marc;ins 

 rough with minute, firm perpendicular, irregularly phiced, 

 aculei. End view triradiate. Spread of arms 58 - 63 f*. 



Brown's Mills, New Jersey. 



The vertical spines, like the thorns of a rose, give this 



plant a distinctive character. 



D, tridentulum, n. sp. 



Cells slender, elongated, linear or slightly tapering, 

 smooth ;semicell with aprominently inflated base; apex crowned 

 with a few large teeth, usually three in view. Diameter 



12—13 fi. 



Ponds, Pleasant Mills, and Browns Mills, N. J. 



Phymatodocis Nordstetianum, n. sp. 



(This genus is based on a plant found in Brazil, in 

 character near the genus Desmidium). Cells closely uni- 

 ted in sheathless filaments; deeply constricted in the middle; 

 filaments quadrangular with sides longitudinally excavated. 



The new species, hitherto found only in a pond at 

 Brown's Mills, New Jersey, differs from the Brazilian plant 

 in being one-fourth smaller, in having the lobes in end 

 view straight, not curved to one side, and in having the 

 sinuses of the cells not narrow linear, but somewhat enlar- 

 ged inwardly and rounded at the base. 



D. elongatum, n. sp. 



Filaments thin ; cells in front view nearly twice as long 

 as wide; in side view nearly 2,5 times longer than broad; 



closely united, without a thickened border at their junction J 



