STAURASTRUM. 131 



angles produced into diverging horn-like processes; end view 

 quadrangular, angles drawn out into four diverging processes, 

 end- obtuse ; membrane granular. 



Diameter 8 //.; length 14//. without the processes; about 

 twice the measure with them. Larger form has with pro- 

 cesses, a diameter of 25 />. 



Not rare in ponds, Pennsylvania, New Jersey. 



St. fraxconicum, Reinsch. (St. divaricatu/m, Wblle.) Plate 

 XL VI. fig. 22. 

 This species is separated from the preceding (St. pugittwm) by 

 its somewhat larger size and by having in end view, five pro- 

 cesses with bifid apices, not obtuse. The typical plant is de- 

 scribed by the author, " membrana glabra, (aul cornua verru- 

 culosa)." < Mir forms are always granular. 

 Diameter about 30/*. with processes. 



This, ami the preceding, ool c mon, but they appear in 



many widely separated localities in New Jersey and Pennsyl- 

 vania. 



St. Haaboeliense, Willi-. Plate KLII, figs. 51-53. 



Small, about one-third more in breadth than length ; oon- 

 triction in the middle forms a wide sinus; semicells in fronl 

 view sub-elliptic, ends bicuspidate, margins dentate ; in ver- 

 tical view triangular or rarely quadrangular, sides sinuate. 

 Membrane granulate. 



Diameter 24 "..; length, 18 ". 



Found this form several times in ponds. New Jersey; it 

 differs slightly from St. tricorm except in the apices, which 

 are not obtuse hut bicuspidate. 



St. botrophtlum, Wolle. Plato X I > 1 1 , figs. 11-13. 



Somewhat longer than broad, distinctly granular ; granules 

 arranged in concentric series; Bemicells, front view, subtrian- 

 gular, with ends broadly truncate, sides moderately convex or 

 nearly straight, con verging, basal angles rounded ; end view 

 triangular, angle- rounded, .-ides -lightly convex or straight ; 

 lateral view, sub-elliptic. 

 Diameter 36-38 ft. 



Collected in marsh ditches near Bethlehem, Pa. In front 

 view it has the appearance of a Cosmarium, like some form 

 of Botrytis, but in side and end view it is a Staurastrum. 



