4* DE8MIDS Or THE [TNTTED STATES. 



the basal inflation the m< t prominent ; ends suddenly con- 

 tracted and truncated; cytioderra coarsely punctate. 



I >iaineter 4060 n.. 



Frequent in ponds from Vermont to Florida. 



I). CLAVATUM, (Kg.,) D. By. Plate IX, fig. 8. 



More slender than the last, suture n<>t prominent, lh-24 

 times longer than broad, sensibly enlarged at the ends, more or 

 less clavate; apices broadly rounded or truncate; cytioderm 

 firm, colorless, densely and irregularly punctate. 



Diameter, smaller forms 2325 ".. larger forms ">> 12 /t. 

 Figure 8 has not the proportionate length. 



Pennsylvania, New Jersey, South Carolina and Georgia. 



D. Trabecula, (Ehrb.,) Naeg. [Doddium Ehrenbergii, Ralfs). 

 Plate IX, figs. 2, 3, 4; and Plate Xljti--. 1-7. 

 [jong cylindrical, eight to twenty times longer than broad ; 

 tapering moderately from the centre to the end-; apices trun- 

 cately rounded, not dentate; suture forming a sharply defined 

 rim, the inflation adjoining often having a smaller one above 

 it. Sometimes there is a contraction near the apex (fig. 2). 

 Cytioderm smooth. Zygospore globose, -mouth, surrounded 

 l>\ a colorless gelatinous envelope. 



Diameter 25-35 //. Length 180^-450/*. 



Occurs frequently, and will probably he found in every 

 State of tie I Inion. 



I), truncatum, Breb. Plate IX, figs. '!, 7. 



("ell- stout, -i\ to eight times longer than broad, with a 

 single inflation at the base of the semi-cell, tapering to the 

 truncate, or broadly rounded, entire, end- ; suture tonus a thick 

 rim which project- on each side. 



I >iameter 50-75 ". 



Florida, Minnesota, Pennsylvania. 



Peculiarities of this species are the large diameter and 

 shortness of cells in comparison with the breadth : the attenu- 

 ated ends, truncate, or broadly rounded apices, solitary infla- 

 tion at the hase of the semi-cells and consequent even sides. 

 Florida furnished the best developed form- 



