130 FRESH-WATER ALGJ3 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. amoennm, Breb. 



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

 utroque polo rotundatum, medio profunde constrictum, sinu angusto, lineari, ambitu granulis 

 margaritaceis achrois obsessum, a vertice ellipticum ; semicellulis oblongo-rotundatis, dorso 

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

 dermate granuloso-verrucoso, verrucis hyalinis in series regulares dispositis. (R.) Species 

 mihi ignota. 



Long. O.OOlt"— 0.1016"; lat. O.OOOSt". (R.) 



Syn. — C. amcenum, Beebisson. Rabenhoest, Flora Europ. Algar., Sect. III. p. 159. 



^ffl6.— 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 glabra. 



** Gytioderm smooth. 



C. CucumiSj CoKDA. 



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

 profunde constrictum ; sinu lineari ; semicellulis angulis inferioribus rotundatis, cytiodermate 

 glabro, haud punctato. 



Z)tam.— Max. long. ^I/ = 0.0026" ; lat. ^ifV' = -0019". 



Syn. — G. Cucumis, Corda. Rabenhoest, Flora Europ. Algarum, Sect. III. p. 161. 



Mab. — 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 ; cytioderm smooth, 

 not punctate. 



Remarhs. — 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 diiFerent 

 conditions ; 16 6, represents a monstrous frond, which had attempted to divide, but 

 had not succeeded in so doing. 



€. depressnin, 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. 



Hob. — Lakes in Florida. 



This species resembles 0. hioculatum, Beeb. ; but the segments are much closer together, and 

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

 Smithsonian Contributions. 



€. pyramidatum, Beeb. 



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



