FRESII-WATEU A LG.E OF THE UNITED STATES. 131 



fere long! us quain latum; sciiiiccllulis brt'vitrr pviviiiiidatis, nngulis iiifci-ioribus ro(iiii<l:ilis, 

 apice (dorso) inodo truiicatis uiodo rotuiidutis, a vcilire late cllijiticis ; cytiodermati' |)inic- 

 tato vel subtilissiuie grauulato. (R.) 



Long. 0.0021"— 0.0037". Lat. nuix. 0.0026". 



Syii. — C. pyramidatum, Brebisson. Rabenhorst, Flora Europ. Algarum, Sect. III. p. 102. 



Hab. — Georgia; Florida; Bailey. Pennsylvania; "Wood. 



Frond scareely twice as long as broad, suljoval ; constriction deep, linear; segments pyramidal, 

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



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



C biociilatiiin, Breb. 



C. parviter, circitcr tam longum quam latum vel paulo longius, ]irofunde constrictuni, .sinu e.x- 

 trorsum ampliato ; semicellulis diainetro duplo latioribus, elliptico-prope he.xagonis angulis 

 obtuse rotundatis, integerrimis aut levis.simc crenulatis; cytiodermate kcvi vel subtilissiuie 

 punctate. (R.) Species niihi ignola. 



Long. 0.000G9". Lat. 0.000G6". (R.) 



Syn. — C. biociilatum, Brebisso.v. R.\beniiorst, Flora Europ. Algarum, Sect. III. p. 1G3. 



Hub— Tihodc Island, (S. T. Olncy) 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. comjiressed s. v. elliptic. 

 Sporangium orbi'cular with conical spines L. -j^'j^" ; B. -ttts"- C^) 



C. ineneg:heuii, Breb. 



C. parvum, tam longum qnam latum, modo paulo-longius, modo paulo-brevius, pmfunile cun- 

 strictum, sinu lineari, e.xtrorsum nou ampliato; semicellulis subquadratis, leviter .sinuato- 

 he.\agonis ; angulis rotundatis, cytiodermate la;vi vel subtillis.sime punctato. (R.) 



Long. J/'— jV" = 0.00103"— 0.0013"; lat. rl/'—rl/' = 0.00081"— 0.00089". (R.) 



Syn. — C. Meneghenii, Brebisso.v. Rabenhorst, Flora Europ. Algar., Sect. III. p. 103. 



nab. — Pennsylvania ; Wood. 



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

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



Reinarh.—Y\g. 18, pi. 12, represents a frond of this species, magnilied 750 

 diameters. 



C crenatiiiii, Ralfs. 



C. oblongum, tertiam partem circa longius quam latum, profunde constriefum, sinu lineari an- 

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

 ambitu crenatis vel regularitcr undulato crunatis, crcuis 10-14; cytiodermate punctato. (R.) 

 Species mihi ignola. 



Long. 0.0021"— 0.0023"; lat. O.OOln". (R.) 



Syn. — C. crenalum, Ralfs, British Desmidiea;, p. 96. 



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



Frond .slightly longer than broad, constriction linear ; segments semiorbicular, cnd.s and .«idcs 

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

 cular, spinous ; spines elongate, slender, swollen at the base and divided at the ape.\. L. ,{ j ; 



Bi " 

 • 5TT • 



