54 DESMIDS OF THE UNITED STATES. 



don ; the contents have escaped, and the parts constituting 

 the cell have separated, contracted and assumed a partial lv 

 inverted position. 



CALOCYLINDRUS, D. By. 



Cells straight, cylindrical, ends rounded or truncate; semi-cells 

 without basal inflation, or longitudinal plication ; chlorophyl parietal 

 or axillary. 



C. Ralfsii, (Kg). Kirch. (Cosmarium cylindricum, Ralfs). 

 Plate XIi; fig. 17. 

 Cells cylindrical, about twice a- long as wide Semi-cells 

 subquadrate in front view, broadest :it the extremity; cytio- 

 derm more or less granulated 



Diameter about '_! 1 fx. 



Peels fresh water, Pennsylvania, New Jersey. 



* 



C. minutus (Ralfs). Kirch. [Penium minutum, Cleve). Plate 

 XII. fig. L2. Plate Y. figs. 1'.'. 20. 

 Cylindrical, 46 times as long as broad, slightly constricted 

 in the middle. emU rounded, membrane smooth. 



Diameter 1 1 -Mi <>. 



Florida, South Carolina, Bailey . Rhode Island, (Olnej 

 This minute and apparently variable plant has not come 



to my notice. It is classed by different authors both a- a 



Penium and a Docidivm. 



C. CUCURBJTA, (Breb.) Kirch {< ['o.stuarium ('uriirhifn Breb). 

 Plate XII. fig. 14. 

 (ells punctate, cylindrical) about twice as long as broad, 

 slightly constricted at the middle, rounded ;it the end-. 



Diameter 22-25 //. 



Pennsylvania ami New Jer* 



C. curtus, (Breb). Kirch. (OosmaHum curium, Breb). Plate 

 XII, figs. 15, 16. 

 Cells somewhat fusiform cylindrical, about twice as long as 

 wide, slightly constricted at the middle, the ends -uboonioally 

 rounded, cytioderm smooth. 

 Diameter 20-32 //. 



