104 Rhodora [JUNE 
U. S., 1884, p. 110, pl. 36, fig. 4 M. fimbriata, var. elephanta Wolle, 
l. c. fig. 3. M. fimbriata, forma simplex Wolle, 1. c. fig. 8. М. sub- 
fimbriata Wolle, 1. c. fig. 7. In this variety the surface usually has no 
ornamentation of spines, the spines on the polar lobe are fewer and 
smaller and the whole lobe less projecting; the basal lobulations of the 
lateral lobes often project beyond the others. Length 186-229 y, 
breadth 180-205 и, polar lobe 40-50 y, isthmus 38 #. Me.: Pushaw 
Stream (Harvey); Scarboro’, frequent (W. West). N. H.: Rochester 
(Wolle). Mass.: Amherst (W. West); Lake Quinsigamond, Worcester 
(Stone); Carver's Pond, Bridgewater! Lake Watuppa, Fall River (H. 
C. no. 15)! Wolle figured and named many forms of this variable 
species but they seem to be but variations of the same thing. His 
forms are included in the above synonymy. 
10. MicnasTrERIAS DENTICULATA Bréb., Alg. Falaise, 1835, p. 54, 
pl. 8; Ralfs, Brit. Desm., 1848, p. 70, pl. 7, fig. 1; pl. 8, fig. 1; Wolle, 
Desm. U. S., 1884, p. 109, pl. 34, figs. 4-8 (forms); W. & G. S. West, 
Brit. Desm., 1905, p. 105, pl. 49, figs. 1-7, pl. 50, figs. 1, 2. Cells 
large, slightly longer than broad, outline subcircular, deeply con- 
stricted, sinus very narrowly linear as are the interlobular ones; semi- 
cells five lobed, polar lobe broadening distally, concave at the apex 
with a median notch, angles rounded, lateral lobes broadly cuneate, 
dichotomously three times divided, ultimate divisions retuse, without 
spines; surface without ornamentation. Length 234—410 x, breadth 
195-300 p, polar lobe 65-76 м, isthmus 25-42 и. Me.: Penobscot 
River at Orono (Harvey). N. H.: Hanover (Edwards); | Intervale! 
Pudding Pond, North Conway! Mass.: Carver's Pond, Bridgewater! 
Lake Watuppa, Fall River! R.I.: Wainskut Pond, North Providence 
(Bailey). This is one of the few species without spines on some por- 
tion of the cell. 
10а. MICRASTERIAS DENTICULATA, var. ANGULOSA (Hantzsch) W. & 
G. S. West., Alg. N. Ireland, 1902, p. 30; Brit. Desm., 1905, p. 107, pl. 
50, figs.3,4. М. angulosa Hantzsch in Rab. Alg., 1862, no. 1407. M. 
denticulata Wood, Fr. Alg., 1873, p. 145, pl. 13, fig. 6. М. radiosa, 
var. punctata West, Desm. Mass., 1889, p. 20, pl. 2, figs. 1, 2. Cells 
more angular than in the typical form, the widest part of the semicell 
usually above the base, lateral lobes but twice divided, surface coarsely 
punctate. Length 245-310 у, breadth 210—300 y, polar lobe 68-77.5 y, 
isthmus 28 м, N. H.: North Woodstock! Mass.: Amherst (W. 
West); Lake Watuppa, Fall River (Н. C. no. 34)! This variety 
