20 Rhodora [January 
13. Ultimate ramuli polysiphonous, of a few, symmetrically placed series of 
cells 16. E. ERECTA 
14. Ultimate ramuli of a single series of cells 15. E. HOPKIRKII 
14. Ultimate ramuli not of a single series of cells 17. E. CLATHRATA 
1. E. micrococca Kiitz., Tab. Phyc., Vol. VL, 11, Pl. XXX, 
fig. 2, 1856; J. G. Agardh, Till Alg. Syst. part 3, 123, 1882 ; De 
Toni, Syll. Alg., Vol. L., 118, 1889. Fronds 1-5 cm. long, 1-5 mm. 
wide, tubular or compressed, simple or slighly proliferous, much 
curled and twisted; cells angular, 4-5 » diam., in no definite order; ` 
thickness of membrane, 15-204. Plate 42, fig. 1, surface; fig. 2, 
cross section. 
The smallness of its cells distinguishes it from all our species but 
E. minima, in which the dimensions are only slightly larger; but the 
latter has a very thin and delicate membrane, while in Æ. micrococca 
it is relatively quite thick, the thickening being specially pronounced 
on the inner side. ‘This gives it a coarser feeling to the touch than 
has Æ. minima. It is common from Marblehead, Mass., north; its 
favorite habitat on the New England coast appears to be the surface 
of shaded steep or vertical cliffs, especially where the flow or drip of 
fresh water keeps it continually moist ; it has been found in Alaska ; 
also on the Atlantic and Mediterranean shores of Europe. Collins. 
(4) 336; (7) 245: (8) 44. Saunders (1) 411. Æ. intestinalis var. 
micrococca, Rosenvinge (1) 957, fig. 545; (7) 157, fig. 54. Exsicc. 
Phyc. Bor.-Am., 66. 
Var. suBsALsA Kjellm. (1) 292, Pl. XXXI, figs. 1-3; De Toni, 
Syll. Alg., Vol. I, 120, 1889. Rachis flattened, with numerous patent 
branches from the edges; much twisted and contorted ; color, dark 
green. 
Reported by Kjellman from the west coast of Greenland, and from 
varios localities in the European Arctic Sea; Rosenvinge raises 
some doubt as to the identity of the Greenland plant. Its habitat 
in the Arctic regions is in lagoons; at Cambridge, Mass., Setchell 
found what is apparently the same plant, growing in muddy places 
in Charles River marshes. It also occurs on the west coast at 
Washington. Collins (8) 44.  Exsicc. Phyc. Bor.-Am., 467. 
2. E. rascrA Post & Rupr. (1) 213 J. G. Agardh, Till Alg. Syst., 
part 3, 125, 1882; De Toni, Syll. Alg., Vol. 1, 120, 1889. Frond 
elongate, tubular-compressed, from a slender stipe, sparingly 
branched; cells 4-6 x 6-8 p, roundish-angular, in no apparent order, 
often containing 2-4 daughter cells. 
In the form of the frond not unlike Æ. intestinalis, but with a 
different arrangement of cells, somewhat recalling //ea fulvescens. 
, The latter, however, is much softer and more gelatinous, and the cells 
are arranged in longitudinal series, and more symmetrical in all 
respects. The characteristic arrangement of cells is not always 
distinct, and in its absence this species is not easily distinguished 
