COSMARIUM. 83 



which give a crenate appearance to the margin ; chlorophyl 

 masses two, often very conspicuous. 

 Diameter 60-78 yu. 



Rather common. The semi-cells are usually near in form 

 to two-thirds of a circle. The transverse view is broadly 

 elliptic. The four chlorophyl nuclei, Avhich are frequently 

 very prominent, two in each semi-cell, probably suggested the 

 name, four-eyed. 



0. Pardalis, Cohn. Plate XLIX, figs. 3-5. 



Cells suborbicular or siibquadrate, equal or slightly longer 

 than broad, constriction narrow linear or often somewhat 

 dilated inwardly, and more or less ampliated outwardly ; 

 semi-cells transversely oblong, subreniform ; base and vertex 

 truncate or concave, angles inferior and superior rounded ; 

 lateral view suborbicular ; vertical view oblong, sides 

 straight ; membrane verrucose, verrucae (papillae) obtuse, 

 regularly arranged in diagonal rows. 



Diameter 54-57 yw. ; length 75-80 ja. ; thickness 39 yu. ; 

 isthmus 18-20 yU. 



Lagerheim reports this African plant from Tewksbury, 

 Mass. It has not come under my notice. Looks like a close 

 relation to some form of C. cons2jersiii/i. The figures repre- 

 sent a front, a lateral and a transverse view, copied from 

 Cohn's figures. 



C. INTERMEDIUM, Dclp. Plate XVI, fig. 12. 



Cells very near the preceding (C. tetrophthalmum), some- 

 what smaller, semi-cells more absolutely semiorbicular, not 

 so elevated. 



Diameter 45-50 ju. 



Habitat same as the preceding. 



C. DBNTATUM, Wolle. Plate XVI, fig. 15. 



Cells about one-half longer than wide; constriction deep, 

 forms gaping sinuses ; cytioderm rather closely set with small 

 pearly granules; the margins of the rounded sides of the 

 semi-cells dentate with large and distant conical projections, 

 or teeth; ten to twelve on each side. The ends broadly 

 rounded are devoid of projecting teeth. End view of cell 

 oval ; lateral view elliptic with a constriction in the middle. 

 Diameter 90-100 /<. ; length 14.5-160 yU. 



This plant has hitherto been found only in Pennsylvania, 

 New Jersey, Florida and Massachusetts. 



It is separated from C. ovole, its nearest kin, by the shape 

 of the semi-cells, which are not triangular, or conical, but 

 broadly oval, and by the nudity of the apices. 



