FRESH-WATER ALG^ OF THE UNITED STATES. 137 



Long. 0.0057"— 0.0065". Lat. max. 0.00346". 



Syn.—E. oblongum, (GEfiviLLE) Ralfs' British Desmidiese, p. 80. 



Hab. — Rliode Island ; Bailey. 



Frond rather more than twice as long as broad, smooth, oblong ; segments 5-lGbed ; lobes nearly 

 equal, cuneate ; lateral lobes, or the basal only, with a broad, shallow, marginal concavity, 

 all their angles rounded, terminal notch linear. 



Empty frond ; f. v. seg. punctate, with three large inflations, on surface near the base, two 

 others above and two on terminal lobe ; tr. v. three times as long as broad, with three sub- 

 distant marginal inflations at each side, and one at each end, in p, broader in proportion, 

 more elliptic, and inflations close; e. v. end lobe notched at opposite external margins. 

 Sporangium orbicular, beset with numerous conical tubercles. ^A.) 



B. Lobi polares evidenter discreti et in apice anguste incisi. 



B. End lobes evidently separated and narrowly incised in the centre. 



E. crassutn, (Baigs.) Ktz. 



E. oblongum, diametro subtriplo longius, profunde constrictum, sinu angusto lineari, e vertice 

 subquadrangulare, ntroque polo profunde excisura, angulis rotundatis ; semicellulis (Ironte) 

 trilobis, basi et in quoque angulo tnmore instructis, lobis lateralibus latissimis unisinuatis, 

 lobo polari paullum prominente, in apice bifido, segmentis late rotundatis; cytiodermate dis- 

 tincte punctato, punctis in series trans versas ordinatis. (R.) 



Long. 0.0051"— 0013". Lat. max. 0.0041". (R.) 



Syn. — E. crassum, (BrSbisson) Ktjtzing Rabenhorst, Flora Europ. Algarum, Sect. III. 



p. 181. 

 Hab. — United States. 

 Frond about twice as long as broad, sub quadrilateral, smooth; segments 8-lobed; basal lobes 



very broad, with a very broad, shallow marginal sinus, in which there is sometimes a slight 



intermediate rounded projection ; end lobe creneate, rounded, terminal notch linear. 

 Empty frond ; f. v. punctate, segments with three inflations below and two above ; tr. v. two or 



three times longer than broad, with three lobes or inflations at each side and one at each end ; 



e. V. end lobe sinuate at opposite external margins. (A.) 



E. ornatnnn, Wood. 



E. oblongum, diametro duplo longius, profunde constrictum, sinu angusto lineari ; semicellulis 

 a fronte trilobatis; lobis basalibus latissimis, nonnihil sinuato-emarginatis, angulis plus minus 

 productis et rotundatis; lobo polari medio profunde lineare inciso, segmentis late rotundatis ; 

 semicellulis a latere bilobatis, lobis basalibus profunde emarginatis et cum angulis plus minus 

 acutis ; cytiodermate distincte ordinatim punctato. 



JWam.— tZ/tt" = .00029". 



Syn. — E. ornatum, Wood, Proc. A. N. S., 1869. 



Eab. — SacoLake; New Hampshire. Lewis. 



E. oblong, twice as long as broad, profoundly constricted ; semicells from the front trilobate ; 

 basal lobe very broad, slightly sinuately-emarginate, angles more or less produced and 

 rounded ; polar lobe medianly profoundly linearly incised, segments broadly rounded ; semi- 

 cells bilobate at the sides, basal lobes profoundly emarginate and with the angles more or 

 less acute ; cytioderm distinctly regularly punctate. 



Bemarks.— This species is close to E. crassum, from which it differs in the pro- 

 portionate length, being only twice instead of three times as long as broad ; in the 

 size being only three-fourths as large; and especially in the peculiar lateral spht- 

 ting, as it were, of the basal lobes. 



18 July, 1872. 



