134 FRESH-WATER ALG^E OF THE UNITED STATES. 



Frond in f. v. about as long as broad, constriction deep, linear; segments quadrilateral, ends 

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

 slightly inflated at the middle and rounded at the ends. Sporangium orbicular, smooth. (A.) 



Remarks. The 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 describe 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. 



Fig. 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. Cellulae fusiformes, cylindricae vel ovules, in medio leviter conslriclse. 



c. Cells fusiform, cylindrical, or oval, lightly constricted in the middle. 



C. Thwaitesii, RALFS. 



C. mediocre, diametro bi-triplo longius, fusiformi-cylindraceum, medio leviter constrictum, am- 

 bitu integerrimum, utroque polo rotundatum ; semicellulis e cylindraceo subconicis, e mcdio 

 in apicem sensim sensimque (sed modice) atteuuatum; cytiodermate Isevi vel indistincte punc- 

 tato. (R.) Species mihi ignota. 



Long. 0.00267" 0.00287". Lat. max. 0.0012". (R.) 

 Syn. 0. Thwaitesii, RALFS, British Desmidieae, p. 109. 

 Hob. Florida ; Bailey. 



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

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

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



C. connatum, BRB. 



C. validum, subrnagnum, leviter compressum, diametro dnplo circa longius, snbpanduriforme, 

 plus minus constrictum, utroque polo late rotundatum, a vertice lato ellipticum; semicellulis 

 subhemisphsericis, ambitu sequabiliter rotundatis, integerriniis ; cytiodermate punctato. (R.) 

 Species mihi ignota. 



Long. 0.0035". Lat. max. 0.00165" 0.0019". (R.) 



Syn. C. connatum, BEBISSON. RALFS, British Desmidiese, p. 108. 

 Ilab. Flqrida ; 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. Cellulse in familias connexse. 

 d. Cells united into families. 



C. Quimbyii, WOOD. (sp. nov.) 



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

 nexis ; semicellulis a fronte ellipticis et diametro subduplo longioribus, a vertice ellipticis, a 

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

 dermate tenue, glabro. 



Diam. Long. TTr V' = 0.001". Lat. a fronte ,&/ = 0.00075" ; a latere 15 ^" = 0.00042". 

 Hab. In aquis puris, New Jersey. 



