STAURASTRUM. 159 



convex, sides somewhat produced and divided into two large 

 diverging mucros; margins ornate with large emarginate 

 verrucae, or more or less conspicuous prominences ; in ver- 

 tical aspect three, or more rarely, four or five angled ; angles 

 produced and divided, and sides furnished with spines as in 

 front view. 



Diameter, including aculei, 70-80 /<. 

 Bamber Pond, New Jersey. 



The form of the semi-cells is more elliptic than trapezoid, 

 but in other points it is a good representative of Lundell's 

 Swedish plant. 



St. monticulosum, Breb. Var. Mfarium, K'ord. Plate LXII, 

 figs. 24-26. 



Semi-cells with a forked spine at each lateral angle, and at 

 the end, two twinned, stout, acute, or furcate prominences ; 

 vertical view usually triangular, angles acute or bifid as the 

 cell is in a horizontal position, or somewhat turned ; sides 

 with four single or two bifid pi'ominences. 

 Diameter 38 //. ; length 33-35 yu. 

 Spring Lake, New Jersey. 



The form I found is not the typical plant, but answers the 

 description of Nordstedt's Norway variety, bif avium. 



St. teicornittum, Wolle. Plate LVITI, figs. 1, 2. 



Large, as long as wide, smooth, semi-cells broad-elliptic 

 with angles terminated by three long, stout, colorless, di- 

 verging, subulate spines; vertical view triangular, sides 

 somewhat concave, or sometimes slightly convex, angles ter- 

 minated with three subulate spines. 



Diameter of body 90-100 /i. ; with the spines 175-200 m- 

 Frequent in Hammonton and other ponds of southern New 

 Jersey. 



St. Nov.a; C^sae^, Wolle. Plate LVIII, figs. 3, 4. 



Cells as long as broad, or somewhat longer, coarsely gran- 

 ulate; semi-cells in front view elliptic, margins crenulate, 

 angles produced into two long subulate, divergent spines; 

 vertical view quadrangular, at angles somewhat constricted^ 

 often producing a mammiform appearance, and drawn out 

 into two, long, subulate spines. 



Diameter without spines 36-40 yu. ; with spines 62-70 pt. 

 This species, hitherto found only in a pond near Hammon- 

 ton, N. J., proves to have a home in Florida also. The plant 



