l;}4 FllESn-WATER ALGiEOr THE UNITED STATES. 



Froiul ill f. V. about as long as broad, constriction deep, linear; segments quadrilateral, ends 

 straigiit, angles rounded, rough all over with minute granules ; e. v. twice as long as broad, 

 sli'i-htly iiiihited at the middle and rounded at the ends. Sporangium orbicular, smooth. (A.) 



Remarks. — Tlie only specimens which I have seen were found in a brick-pond 

 below the city in the month of June. They agree well with the descriptions, ex- 

 cepting in that I should descril)e their central inflation as pronounced. The sinuses 

 also are ampliate or hollowed out within. The granulations are quite large, and 

 are arranged somewhat irregularly in rows. 



Fi". 15, pi. 13, is a view of the front of the frond magnified 460 diameters; 

 fig. 10, pi. 21, the outline of the lateral view. 



c. Ccllula; f US/formes, cylindricse vel ovales, in medio leviter constrictse. 



c. Cells fusi for in, cylindrical, or oval, liijhlly constricted in the middle. 



C. Tliw.TiJesii, T.alfs. 



C. mediocre, diametro bi-triplo longius, fusiforrai-cylindraceura, medio leviter constrictura, am- 

 bitu integerrimum, utruque polo ri.itundatuin ; sfmicellulis e cylindraceu subconicis, e medio 

 in apicem sensim sensimque (sed modice) attenuatum; cytiodermate laevi vel indistincte punc- 

 tate. (R.) Species inihi ignota. 



Long. 0.0026t"— 0.00287". Lat. mas. 0.0012". (R.) 



Syn. — C. Tliwaitesii, Ralfs, British Desraidiese, p. 109. 



Ilah. — Florida ; Bailey. 



Frond in f. v. two or three times longer than broad ; constriction a very shallow groove ; seg- 

 ments subcylindrical, with vouuded ends ; endochrome scattered ; e v. circular, or very slightly 

 compressed ; e. f. not punctate, or puncta very indistinct. (A.) 



€. connatiim, Breb. 



C. validum, sulimagnum, leviter eompressura, diametro duple circa longius, subpandnriforme, 

 plus minus constrictum, utroque polo late rotundatum, a vertiee lato ellipticum; semicellnlis 

 subhemisphasricis, ambitu sequabiJiter rotundatis, integcrrimis ; cytiodermate punctate. (R.) 

 Species mihi ignota. 



Long. 0.0035". Lat. ma.x. 0.00165"— 0.0019". (R.) 



Sf/n. — -C. connatiim, Brebisson. Ralfs, British Desmidicfe, p. 108. 

 Ilab. — Florida; Bailey. 



Frond large, in f. v. about one-half longer than broad ; constriction shallow ; segments about 

 two-thirds of a circle, coarsely punctate, and with a distinct, sometimes striated, border; e. v. 

 circular. (A ) 



d. Gellulae in familias connexse. 

 d. Cells united into families. 



C. <(llillil>yii, Wood. (sp. nov.) 



C. cellulis parvis, sub-ellipticis, medio profunde constrictis, in familias eopulis hyalinis con- 

 nexis; scmicellulis a fronte ellipticis et diametro subduplo longioribus, a vertiee ellipticis, a 

 latere rotundatis; sinu lato; marsis chlore-phyllaceis in quaque semicellula singulis; cytio- 

 dermate tenue, glabre. 



/)iani._Long. „>^" = 0.001". Lat. a fronte ^i^^" = 0.00075" ; a latere jj-J^/ = 0.00042". 

 Hab. — In aquis puris, New Jersey. 



