136 FRESn-WATER A L G ^E OP THE UNITED STATES. 



outliue 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 

 tlie 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 tjic front view of a frond of this plant; fig. 5, pi, 20, 

 the outline of a two-thirds view, and tig. 5 a, the outline of a lateral view, all mag- 

 nified 450 diameters. 



E. Terrucosiini, Eiirb. 



E. maginira, late ovatum, vix longius quam latum, medio profundo constrictum, sinu extrorsum 

 dilatato; souiicellulis trilobatis, lobis triangularibus, divergeutibus, apice late et profunde 

 sinuatis ; a latere ovato-oblongum, siiiuato-lobatum, lobis octo in apice rotuudatis, polaribus 

 singulis porrectis, latcralibus teruis ; cytiodermate granulato-verrucoso. (R.) Species mihi 

 iijnota. 



Long. 0.0036"— 0039". (R.) 



Syn. — E. verrucosum, Eheenbero. Rabenhorst, Flora Europ. Algarum, Sect. III. p. 119. 



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



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

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

 sinus. 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. ^e IIS 111 a til 111, Breb. 



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

 oblongum, ambitu sinuato-lobatum, lobis 8 couforraibus, rotuudatis ; 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, ca;teruin laivi. (R.) Species mihi ignota. 



Long. 0.00224"— 0.0029". Lat. 0.00157'- 0.001*7". (R.) 



Syn. — E. gemmatum, Brebisson. Rabenhorst, Flora Europ. Algar., Sect. III. p. 180. 



Hab. — 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 ; fr. 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. obloiig^iiin, (Grev.) Ralfs. 



E. magnum, diametro duplo triplove longius, oblongum, profunde constrictum, sinu angnsto, 

 a latere oblongo-lanceolatum, utroque polo truncato leniter retusura, ambitu undulato- 

 sinuatum ; semicellulis (fronte) sinuato-quinquelobis, basi et in quoque lobo tumore instrnctis, 

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

 polari late euneato in apice profunde inciso, angulis omnibus rotundatis, cytiodermate la;vi ; 

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

 ignota. 



