136 FRESH-WATER ALG^ OF THE UNITED STATES. 



outline in which all the sinuses are of similar form, and the central and basal lobes 

 are about equal size; whereas, when viewed from the front, the basal lobe is much 

 the broader. When the desmid is viewed from the side it is seen to be enlarged 

 in the centre, and provided with two distinct umbonations each side of the com- 

 paratively narrow central sinus. 



Fig. 10, pi. 12, represents the front view of a frond of this plant; fig. 6, pi. 20, 

 the outline of a two-thirds view, and fig. 6 a, the outline of a lateral view, all mag- 

 nified 450 diameters. 



E. Terrucosuni, Ehrb. 



E. magnum, late ovatum, vix longius quam latum, medio profande constrictum, sinu extrorsum 

 dilatato ; semicellulis trllobatis, lobis triangularibus, divergentibus, apice late et profunde 

 sinuatis ; a latere ovato-oblongum, sinuato-lobatum, lobis octo in apice rotundatis, polaribus 

 singulis porrectis, lateralibus ternis ; cytiodermate granulato-verrucoso. (R.) Species mihi 

 ignota. 



Long. 0.0036"— 0039". (R.) 



Syn. — E. verrucosum, Ehrenberg. Rabenhoest, Fl«(,ra Europ. Algarum, Sect. III. p. 1T9. 



Eab. — South Carolina; Georgia; Florida; Rhode Island; Bailey. 



Frond somewhat longer than broad, rough all over with conic granules ; segments 3-lobed, 

 somewhat divergent, all the lobes broad, cuneate, with a. very broad, shallow, or external 

 sinns. Empty frond; f. v. segments with one large circular basal inflation on surface, one 

 smaller on each side, and two others on the end lobe ; s. v. segments inflated at the base, 

 narrowed into a short neck, end dilated with a central sinus ; e. v. oblong, with three infla- 

 tions at each side, one at each end, end lobe 'having 4 divergent lobelets. (A.) 



E. g^emmatnin, Br£b. 



E. mediocre, diametro duplo longius, profunda constrictum, sinu angusto lineari, a vertice ovato- 

 oblongum, ambitu sinuato-lobatum, lobis 8 conformibus, rotundatis ; semicellulis trilobatis, 

 basi tumoribus 3 in seriem dispositis, lobis in apice profunde emarginatis, lobulis rotundatis, 

 lobo polari dilatato et paulum producto ; cytiodermate in tumoribus et lobulis granulato- 

 punctato, cEeterum leevi. (R.) Species mihi ignota. 



Long. 0.00224"— 0.0029". Lat. 0.00157"— 0.0011". (R.) 



Syn. — E. gemmatum, Bk:6bisson. Rabenhorst, Flora Europ. Algar., Sect. III. p. 180. 



Hah. — Rhode Island ; Bailey. 



Frond scarcely twice as long as broad ; segments 3-lobed, lateral lobes horizontal, deeply emar- 

 ginate, the protuberances minutely granulate; end lobe dilated, its dilatations inclined 

 upwards, and minutely granulate ; ends with a deep rounded emargination. Empty frond 

 slightly punctate ; f. v. segments with three granulate inflations near the base ; tr. v. broadly 

 elliptic, with three granulate inflations at each side and one at each end ; e. v. end lobe cruci- 

 form, lobelets rounded, granulate. (A.) 



E. oblongnm, (Grev.) Ralps. • 



E. magnum, diametvo duplo triplove longius, oblongum, profunde constrictum, sinu angusto, 

 a latere oblongo-lanceolatum, utroque polo truncate leniter retasum, ambitu undulato- 

 sinuatum ; semicellulis (fronte) sinuato-quinquelobis, basi et in qnoque lobo tumore instructis, 

 lobis lateralibus in apice dilatato sinuato-retusis, inferioribus^ latioribus quam superior., lobo 

 polari late cuneato in apice profunde inciso, angulis omnibus rotundatis, cytiodermate laevi ; 

 zygosporis globosis verrucosis, verrucis obtuse conicis achrois byalinis. (R.) Species mihi 

 ignota. 



