i i; i-:s ii -\v ATI: i: AI.<;.I: OK TIM: I.MTKD STATES. 157 



//ill. America ; Klircnlicrg. 



Frond in front view broader than lonp; constriction deep, acute not linear; segments nuln-l lip- 

 tic, sometimes irrcirulur spines subulate, geminate, marginal, central protulHTanee cylindrical, 

 truncate border minutely dentate. L. (not including spines) jj ". B. ? J," to jjj". 



JL rriotntiim, HKKII. 



X. ]>arvuni, lu-ve ; scmicellulis subhasmispherico-rcniformibus, utroque polo aculeo unico in- 

 curro, ainbitu aculcis octo geminatia, a dorso ovato-ellipticis, utroque polo aculeis tcruiH, in 

 incdin plcniini|iic aculco abbreviate. (R.) Species ntihi ignota. 



lHam. 0.00196". R. 



A . rifliilinn, HiiKiiissox. RALF8, British Desmidieae, ct RABENIIORST, Flora Kurop. 

 Algarum, Sect. III. p. -JiM. 



Hub. South Carolina; Georgia; Florida; Bailoy. 



Frond rather longer than broad; constriction deep, linear ; segments subreniform or truncate 

 at ends ; spines straight or curved, subulate, marginal, one at each side, at the base of the 

 segment, solitary, the others geminate, in four pairs ; central protuberance short, conical. (A.) 



\.coroiintiim. K.mui. 



X. scmicellulis subglobosis binis, aculeatU, ubique aspcris, aculois crassis apice truncatis triden- 

 tato-coronatis quatuor utriuque dorsalibus, uno utrinquo laterc uiedio. (R.) Species mihi 

 ignota. 



Syn. X coronatum, EHRE.NBERO, Vcrbreitung, p. 138, ct RABENIIORST, Flora Europ. Alga- 

 rum, Sect. III. p. 224. 

 Asteroxanthium coronatum, KUTZINO. RABENHORST, (loc. tit.) 



JIdb. America ; Ehrenberg. 



/,' mark. Mr. Archer appears to think that this species is simply a form of 

 iraslrum furcigerum. (BREB.); see Pritchard's Infusoria, p. 743. 



X. f;i< i< iilntiim, KIIKH. 



X. parvum, singulum, constrictiono profundo linear! ; cytiodermatc Irevi vcl Rubltcvi ; semieel- 

 lulis oblongo-reniformibus vel hexagonis, diametro duplo longioribus, ambitu aruleis gracililms 

 geminatis 4-C, a dorso ellipticis, utroque polo aculcis quatuor instructis. (R.) Species mihi 

 ignota. 



Diam. 0.00228" 0.00256". (R.) 



Syn. -.Y./aaei'cu/a/uwi.EnRENBERa. RABENHORST, Flora Enrop. Algarnm, Sect. III. p. 223. 



Hab. South Carolina ; Georgia ; Florida ; Rhode Island ; Bailey. 



Frond about as long as brood ; constriction deep, linear ; segments somewhat reniform or sub- 

 hexagonal, twice as broad as long, spines slender, subulate geminate, marginal, in four or six 

 pairs ; central protuberance short, conical, somewhat truncate. (A.) 



Genus ARTHRODESMUS, EHRB. 



Cellulaj profunde constrictae ; semicelluloe compresses aut oblongee, utroqne polo acnleo subulato 

 firmo instructor, aut quadrangularcs, angulis in aculenm rectum vel ciirvum prodnctis, a dorso vel 

 elliptic vel fusiformes. Massa cblorophyllacea in fascias quatuor radiantes disposita. (R.) 



Cells profoundly constricted; semicells compressed or oblong, furnished at each end with a subu- 

 late spine, or else quadrangular with the angles produced into straight or curved spines, the dorsal 

 aspect, elliptic or fusiform. Chlorophyl masses disposed in four radiating fascia. 



