FHKS1I-U ATKK ALG^I OF THE UNITED STATES. 133 



rotundutis, dorso triiiu-ato-rntundaiis, margine crenulato-dentatis, a dorso oblongis, 

 mediu ventrifo.-U, uinMjuc polo plus miim* tuiuidis ; cyliuderuiate grauulato margaritifuro. 

 (B 



Long. 0.0010" 0.0012." Lat. 0.0013" 0.0015". (R.) 



,Syn. C. comniitsiiiiriili-, l!iu;iii.ssu.\. RAUK.NHORBT, Flora Europ. Algarura, Sect. III. p. 170. 



Hab In lacu. While Mountains, New Hampshire ; (Dr. F. W. Lewis) 



Frond small, in f. v. one-third broader than long; constriction very deep, rounded; segments 

 iiarrow-reiiifortn, with a central, somewhat truncate projection, produced by the continuation 

 of the cent nil inflation, rough on the inflation and on the extremities, with somewhat large 

 pearly granules, e. v. three times longer than broad, constricted between the central inflation 

 and the rounded extremities. Sporangium as in C. ornalum. (A.) 



Remark*. I have seen but a single specimen of this species which differed from 

 the typical form, in having the sinus very narrow in its outer portion, and in being 

 shorter. 



Fig. 1(5, pi. 13, represents the frond of this specimen, magnified 750 diameters. 



C. < ;rlalimi. RALFS. 



C. suborbicularc, profande constrictum ; sinu angustissimo linear! ; semicellnlis inciso-crenatis, 

 angnlis rotundatis, a vertice medio nonuihil inflatis; cytiodenuate granulato, granulis in 

 series regulariter circulares positis. 



Diam. Long. T8 VW = -0017". Lat. ^^ = -0014". 



Syn. C. culalum, RALFS, British Desmidieaa, p. 103. 



llab. In Btagnis prope Aiken, South Carolina. (Ravenel.) 



Suborbicular, profoundly constricted ; sinus very narrow, linear ; semicells inciso-crenate, 

 angles rounded, when seen from the end somewhat inflated in the middle ; cytioderm granu- 

 late, granules placed in circular series. 



Remarks. This species was collected by Prof. Ravenel in a quiet ditch near 

 Aiken, South Carolina, sparsely scattered amidst innumerable diatoms and desmids. 

 The number of the crcnations appears to vary. In the few individuals I have seen 

 there were six end ones besides the two very broad basal ones, if the latter can be 

 called crcnaturrs. Ralfs gives six as the total number, and yet every one of his 

 figures has many more. So I think the number a character of but little import- 

 ance. The circular arrangement of the granules is not so positive and regular in 

 the specimens I have seen, as is represented in the figure of Ralfs, otherwise the 

 agreement is perfect. 



C. Broomei, TIIWAITES. 



C. subparvum, plcrumque tarn lonpum quam latum, nonnnnqnam paulo longins, obtuse qnad- 

 rangnlare, profnndc constrictum, sinu angustissimo linear! ; gcmicellulis oblongo-quadrangulis, 

 diametro duplo longioribns, angnlis et inferioribns et snperioribus obtuse rotundatis, venire 

 snbplanis, dorso latissime trnncatis et saepius leniter retusis vel plane convexis; cytioder- 

 mate granulato-margaritaceo, granulis in seriebus snbrectis collocatis. (R.) 



Long. 0.00194" 0.0022". Lat max. .002", thick .0015". 



Syn. C. Eroomei, THWAITM. RALFS, British Desmidieoe, p. 103. 



Hab. Georgia ; Bailey. Prope Philadelphia ; Wood. 



