FRESH-WATER ALG^ OF THE UNITED STATES. 131 



fere longius quam latum ; semicellulis breviter pyramidatis, angulis inferioribus rotundatis, 

 apice (dorso) modo truncatis modo rotundatis, a vertice late ellipticis ; cytiodermate pune- 

 tato vel subtilissime graiiulato. (R.) 



Long. 0.0021"— O.OOSr'. Lat. max. 0.0026". 



Syn.— G. pyramidatum, Brebisson. Rabenhorst, Flora Europ. Algarura, Sect. III. p. 162. 

 -Haft.— Georgia ; Florida; Bailey. Pennsylvania; Wood. 



Frond scarcely twice as long as broad, suboval ; constriction deep, linear ; segments pyramidal 

 rounded at basal angles, somewhat truncate at the ends, punctate ; e. v. broadly elliptic. (A.) 



Remark.— Fig. 14, pi. 13, is a drawing of this species. 



€. biocnIatniiL, Br£b. 



C. parviter, circiter tam longum quam latum vel paulo longius, profunde constrictum, sinu ex- 

 trorsum ampliato ; semicellulis diaraetro duplo latioribus, elliptico-prope hexagonis angulis 

 obtuse rotundatis, integerrimis aut levissime crenulatis ; cytiodermate Isevi vel subtilissime 

 punctato. (R.) Species mihi ignota. 



Long. 0.00069". Lat. 0.00066". (R.) 



Syn.~G. bioculatum, Brebisson. Rabenhorst, Flora Europ. Algarum, Sect. ITI. p. 163. 



Hab.— Rhode Island, (S. T. Olney) Thwaites. 



Frond minute, about as long as broad, constriction deep, producing a gaping notch at each 

 side ; segments about twice as broad as long, elliptic, smooth ; s. v. compressed s. v. elliptic. 

 Sporangium orbicular with conical spines. L. „ij-^" ; B. jj^rs". (A.) 



C. ineneg^heiiii, Br:eb. 



C. parvum, tam longum quam latum, modo paulo-longius, modo paulo-brevius, profunde con- 

 strictum, sinu lineari, extrorsum non ampliato; semicellulis subquadratis, leviter sinuato- 

 hexagonis ; angulis rotundatis, cytiodermate laevi vel subtillissime punctato. (R.) 



Long. ^V"-- yV" = 0.00103"— 0.0013"; lat. ^l^"'—^y" = 0.00081"-0.0008e". (R.) 



Syn. — C. Meneghenii, Brebisson. Rabenhorst, Flora Europ. Algar., Sect. III. p. 163. 



Hah. — Pennsylvania ; Wood. 



Frond very minute, rather longer than broad, constriction linear ; segments subquadrate, bicre- 

 nate at the sides and ends, smooth ; e. v. elliptic. (A.) 



Remarh.—Yig. 18, pi. 12, represents a frond ,of this species, magnified 750 

 diameters. 



€. crenatnin, Ralfs. 



C. oblongum, tertiara partem circa longius quam latum, profunde constrictum, sinu lineari an- 

 gusto ; semicellulis e basi lata subsemicircularibus, dorso plus minus depressis vel truncatis, 

 ambitu crenatis vel regulariter undulato crenatis, crenis 10-14; cytiodermate punctato. (R.) 

 Species mihi ignota. 



Long. 0.0021"— 0.0023"; lat. 0.0015". (R ) 



Syn. — C. crenatum, Rales, British Desmidieas, p. 96. 



Sa6.— Rhode Island ; (S. T. Olney) Thwaites. 



Frond slightly longer than broad, constriction linear ; segments semiorbicular, ends and sides 

 broadly rounded, crenate or minutely undulate at margin ; e. v. elliptic. Sporangium orbi- 

 cular, spinous ; spines elongate, slender, swollen at the base and divided at the apex. L. ■i\-s" ; 

 T? 1 " 



