EUASTRUM. 109 



Tar. CUSPID ATUM, WoUe. Plate XXXIII, figs. 3, 4, 5. 



This variety differs in being more depressed, squatty, in 

 having the lateral lobes cuspidate, end lobe not so wide, and 

 greater thickness to the body of the cell. End vie\r fig. 5) 

 shows a more angular figure with end lobe cruciform ; cytio- 

 derm punctate. 



The typical form I found in various places in New Jersey ; 

 the variety odIv in a Sphagnuii} bed in a pond near Newfield, 

 New Jersey. 



The original plant was found in Sweden ; our true form 

 agrees well in size and figure with it. 



E. ANSATUM, "Ehrb. , Ealfs. {E. Balfsii, Eab.) Plate XXVIII, 

 figs. «, 9, 10 ; and Plate XXXIII, figs. 11, 12. 

 Semi- cells inflated at the base, and tapering upwards to 

 the notched but not dilated extremity ; end view cruciform. 

 Cytioderm punctate. There appear to be two distinct va- 

 rieties of this .species, perhaps distinct i)lants ; the one twice 

 the size of the other. 



Diameter normally 2.5-36 fj. Var. majof, diameter 62-74 jj. 

 Frequent in ponds and quiet waters, widely distributed. 

 The various sizes may represent different stages of develop- 

 ment. 



E. DIDELTA. (Turp. ; Ealfs. Plate XXXIII, figs. 9, 10. 



Cells rather more than twice as long as broad ; semi-cells 

 pyramidal, inflated at the base and again at the middle ; end 

 scarcely dilated, more or less rounded, notch linear ; trans- 

 verse view shows four shallow lobes on each side and one 

 on each end. Cytioderm punctate. 

 Diameter 50-62 ju. ; length luQ-12.5 /<. 



There is a smaller form which measures about one-fourth 

 less. Specimens often very close to the following, £!. ampul- 

 laceum. Transverse view nearly the same. 

 Frequent everywhere, north, south and west. 



E. PEOTINATUM, Breb. Plate XII, figs. 10-12. 



Semi-cells three lobed, terminal lobe dilated, usually en- 

 tire; lateral lobes broad, making the basal portion of the 

 semi-cell somewhat quadrilateral, horizontal, at each side 

 emarginate ; lateral view cuneate, with two Sft'ellings near 

 the base and one at the apex ; transverse view oval with 

 three lobules on each side and one or imperfectly two at each 

 end. 



Diameter 40-50 /<. ; length about 75 ja. 



