CALOCYLINDRUS. 59 



C. MINUTUS. (Ralfs), Kirch. (Penium minutum, Cleve). Plate 



XV, fig. 12. Plate V. figs. 19, 20. 



Cylindrical, 4-6 times as long as broad, slightly constricted 

 in the middle, ends rounded, membrane smooth. 

 Diameter 11-16 //. 



Florida, South Carolina, (Bailey), Rhode Island, (Olney). 

 This minute and apparently variable plant has not come to 

 my notice. It is classed by different authors both as a Penium 

 and a Docidium. 



C. CUCURBITA, (Breb.), Kirch. (Cosmarium Cucurbita, Breb.) 



Plate XV, fig. 14. 



Cells punctate, cylindrical, about twice as long as broad, 

 slightly constricted at the middle, rounded at the ends. 

 Diameter 22-25 /<. 



Pennsylvania and New Jersey. 



C. CURTUS, (Breb.), Kirch. ( Cosniarium curtum, Breb.). Plate 



XV, figs. 15, 16. 



Cells somewhat fusiform cylindrical, about twice as long 

 as wide, slightly constricted at the middle, the ends sub- 

 conically rounded, cytioderm smooth. 

 Diameter 20-32 p. 



Pennsylvania, New Jersey, and other States. 



Fig. 16 represents a small form collected several succeeding 

 Summers, in gelatinous masses on the muddy bottom of a 

 small pool ; thousands were present ; the other (fig. 15) is the 

 larger, typical form. 



C. CORDANUM, Breb. Plate XLIX, fig. 28. 



Diameter about half the length ; gentle and slightly con- 

 stricted in the middle ; ends round or somewhat truncate ; 

 cytioderm lightly granular or punctate. End view circular. 



Diameter 26-27 yu. ; length 47-50 yu. ; isthmus 17-19 JM. 



This form is reported by W. B. Turner, as found in Nova 

 Scotia. 



C. CONNATUS, (Breb.), Kirch. (Cosmarium connatum. Breb.) 



Plate XV, figs. 8, 9. 



Cells short and thick, subcylindrical, about one and one- 

 half to two times longer than broad, ends broadly rounded ; 

 constriction forms a wide, shallow sinus ; cytioderm dis- 

 tinctly punctate. 

 Diameter 45-75 ju. 



Pennsylvania, New Jersey, Florida, New York, Vermont, 

 Minnesota, etc.; probably distributed everywhere. 



