130 FRESH- WATER ALGJi OF THE UNITED STATES. 



found on the continent, were collected by myself in " Shepherd's Mill Pond," near 

 Bridgeton, Cumberland County, New Jersey. 



Fig. 7 a, pi. 21, represents the outline of a frond magnified 460 diameters. 



C. amcennm, BREB. 



C. mediocre, oblongum cylindricum, levitcr compressum, diametro duplo fere triplove longius, 

 utroque polo rotundatum, medio profunde constrietum, sinu angusto, linear!, nmbitu granulis 

 margaritaceis achrois obsessum, a vertice ellipticum; seraioellulis oblongo-rotundatis, dor.so 

 alte convexis, lateribus vero rectis parallelis, angulis inferioribus rectis et subacutis ; cytio- 

 dermate granuloso-vcrrucoso, verrucis hyaliuis in series regulares dispositis. (11.) Species 

 mihi ignota. 



Long. 0.0017" 0.101G"; lat. O.OOOSt". (R.) 



Syn C. amoenum, BREBISSON. RABENIIORST, Flora Enrop. Algar., Sect. III. p. 159. 



Hab. Florida ; Bailey. Rhode Island (S. T. Olney); Thwaites. 



Frond twice as long as broad, sides parallel, ends rounded, constriction deep, linear ; segments 

 rough with crowded obtuse papilla-like pearly granules ; s. v. much compressed, about thrice 

 as long as broad ; e. v. elliptic. (A.) 



** Cytiodermate glabro. 

 ** Cytioderm smooth. 



C. Cucumis, CORDA. 



C. ovale ellipticum, utroque polo late rotundatum, tertiam partem vel duplo longius quam latum, 

 profunde constrietum ; siuu linear! ; semicellulis angulis inferioribus rotundatis, cytioderinate 

 glabro, hand punctato. 



Diam. Max. long. ^ 5 " = 0.0026" ; lat. 7 ' g 5 " = .0019". 



Syn. C. Cucumis, CORDA. RABENHORST, Flora Europ. Algarum, Sect. III. p. 161. 



Hab. South Carolina ; Georgia; Florida; Bailey. Pennsylvania; Wood. Saco Lake, (Lewis.) 



Oval or elliptic, at each end broadly rounded, one-third to twice as long as broad, profoundly 

 constricted; sinus linear; semicells with their inferior angles rounded ; cytiodurm smooth, 

 not punctate. 



Remarlcs. This species is very abundant around Philadelphia. The semicells 

 generally each contain two large globular masses placed near the median line, 

 which are sometimes hidden by the crowded endochrome. 



Figs. 15, 15 a, pi. 12, represent this species with their endochrome in different 

 conditions; 15 b, represents a monstrous frond, which had attempted to divide, but 

 had not succeeded in so doing. 



C. depressum, BAILEY. 



" Elliptical, binate, division in the plane of the longest axis. Segments entire, nearly twice as 



long as broad, rounded above, very much flattened at base. 

 Hab. Lakes in Florida. 



This species resembles G. bioculatum, BREB. ; but the segments are much closer together, and 

 are angular, not rounded at the basal extremities." BAILEY. Microscopical Observations. 

 Smithsonian Contributions. 



C. pyramidatiim, BREB. 



C. mediocre, ovale vel subovale, utroque polo truncatum, medio profunde constrietum, duplo 



