11 DESMTDS OF TTTF. UNITED STATES. 



( '. AMBLYONEMA, Ehrb. 



A form bearing this name was accredited to the United 

 States by Dr. Ehrenberg. Prof. Bailey, about thirty years since, 

 examined the character of the plant, and pronounced it the 

 same a- ( '. lineatum. 



C. scutum, Breb. Plate VII, figs. 11. 12. 



Small, slightly bent, 612 time- longer than broad, gently 

 tapering from the middle to the rounded ends; cytioderm 

 colorless and smooth. Zygospores angular. 



Diameter !-l 1 n. 



Nut rare in marsh pools, Pennsylvania and New Jersey. 



C. Dian.e. Ehrb. Plate VII, figs. 8, 9. Plate VIII, fig. . 



Crescent shape, - itimes a lull semi-circle a- variety 



arcuatum, Breb., attenuated from the middle t<> the rather 

 sharp end-, vacuole not definitely defined; transverse striae 

 sometimes evident. Ends are separated by aboul 1<> diameters. 

 Zygospore spherical, smooth. 

 Diameter 16-20 u. 



Quiet waters Rhode [aland to Florida. 



( . acuminatum, Kg. Plate VII, figs. 18, 19. 



Similar to Diance, somewhat larger and less curved, ends 

 sharper, vacuoles more distincl ; membrane very finely striate, 

 or smooth. 



I diameter 2528 /'. 



Nut rare in marsh pools; conjugated <-ell> frequent. 

 Pennsylvania. 



I . Jenneri, Ralfs. Plate VII, fig. ". 



Crescent shaped, -mall, slightly tapering, -i.\ to eight times 

 longer than broad, ends obtusely rounded ; vacuole large con- 

 taining many active granules ; cytioderm colorless, -mouth. 

 Diameter aboul 1 I ".. 



Rhode Island ' Bailey i; Pennsylvania, New Jersey. 



' Venus, Kg. Plat- VII. fig. <;. 



Small, more or less -lender, nearly semi-circular, eight to 

 twelve time- longer than the diameter; graduallv tapering 



