< LOBTERTUM. I 5 



from the middle to the sharp ends ; vacuole distinct : cytioderm 

 colorless and smooth; chlorophy] homogenous. 

 1 diameter 810 u. 



South Carolina, Ravenel); Pennsylvania, New Jersey, 

 frequent. 



( '. parvu.lum, Naeg. Plate VII, fig. 7 ; and Plate \' 1 1 1. fig. 16. 

 Six to eight times as l >hli as wide; differs ('nun < '. Venui 

 in being rather less arched and stouter, vacuoles not so well 

 defined, and chlorophy] lamina more evident. 

 I diameter 1 2 ". 



^i' ii<>\ III.- -Cells falcate as the preceding ; upper margin ven convex, lower 

 side concave with :i more or less conspicuous central inflation, ends tapering. 

 Zygospores Bpherical, Bn th. 



C. Ehrenbergii, Menegh. Plate VII, fig. 16. 



Large, stout, five to six times as long as the central diameter ; 

 upper margin very convex, lower side ventricosely much 

 inflated; ends rounded; cytioplasm with large granules, 

 numerous, scattered ; no striae, mid no central suture evident. 

 Of the zygospore, A.rcher says, " it is smooth, placed between 

 the slightly connected empty conjugating fronds, the endo- 

 chrome during the process of conjugation emerging from the 

 opened apex of a shorl conical extension from the under side of 

 each younger segment or shorter one) of each pair <>f recently 

 divided fronds; the conjugating fronds being produced imme- 

 diately previously by the self-division of a pair of old fronds 

 two sporangia (zygospores) being thus the ultimate produce 

 <>t the 1 wo original fronds." 



I liameter 751 1" u. 



4 



Ponds, Pennsylvania and New Jerse) : common. 



Var. IMMANE, Wolle. Plate VII, fig. 17. similar to the typical 

 form except in size. 

 Diameter 208 fi. 



Not infrequent in Budd's lake, and larger ponds of New 

 Jersey. 



C. MONILIFERUM, Ehrb. Plate Y 1 1 . fig. 16. 



\ ery near C. Ehvenbergii, but somewhat smaller, six to 

 nine times longer than broad, ends subacute; cytioderm light 



