STAURASTRTTM. 145 



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 prominence-. 

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



Spring Lake, New Jersey. 



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

 description of Nordstedt's Norway variety, bifarium. 



St. tricornutum, Wblle. Plate XLYII. figs. 1, 2. 



Large, as long as wide, smooth, semicells broad-elliptic with 

 angles terminated by three hmg, stout, colorless, diverging, 

 subulate spines* vortical view triangular, side- somewhat con- 

 cave, or sometimes slightly convex, angle- terminated with 

 three subulate spines. 



Diameter of body 90-100/*.; with the -pine- 175-200 fJU 

 Freipient iu EEammonton and <>t her ponds of southern New 

 Jersey. 



St. Xov.i: Oesarile, Wolle. Plate KLVII, figs. : > ., 4. 



('ells a- long as broad, or somewhat longer, coarsely granu- 

 late ; -einicells in front view elliptic, margins crenulate, angles 

 produced into two long subulate, divergenl -pine-; vertical 

 view quadrangular, at angle- somewhat constricted often pro- 

 ducing a mammiform appearance, and drawn out into two, 

 long, subulate spine-. 



Diameter without spines 3640 (i.) with spines <!2-7<> ft. 



The hitherto only locality for this distinct form is a pond 

 near Hamniouton, N. J. 



St. longispinum, Bailey. Plate XLI, i\^. 7. 



Large, smooth, triangular, with two long spines at each angle. 



Diameter of body 75 >>..\ with spines 15<> //. 



Lakes in Florida (Bailey). 



St. quadranoulare, Breb. Plate XLI, figs. 1-4. 



Cells smooth, nearly square, divided by a deep, linear con- 

 striction into rectangular-oblong semicells with a few marginal 

 spines or teeth ; end view quadrilateral, sides more or less 

 concave, angles truncate and emarginate or dentate. 



Diameter 23-30 u. 



Not infrequent in ponds of Pennsylvania, New Jersey, and 

 Florida. 

 10 



