252 
W. E. WADE 
Penium Bréb. 
Peniiim polgmorphuni Perty. Baraga, Barry, Chippewa and Hough- 
ton Counties. 
Pleurotaeniiim Naegeli. 
Pleurotaenium constrictum (Bail.) Wood. Berrien and Chippewa 
Counties. 
P. minutiim var. elongatnm (West and West) Cedergren. Alger 
County. 
P. mimifuin var. gracile (Wille) Krieger. Chippewa County. 
P. siibcoronulatnm var. detum West and West. Gogebic County. 
P. trabecula var. rectissimu.n 2 West and West. Specimens froin 
Barry County are assigned here ou the basis of cell nieasure- 
ineiits although the slightly dilated apices which are characte- 
ristic of this variety are not présent. 
P. verrucosiim (Bail.) Lund. Gogebic County. 
Triploceras Bail. 
Triploceras verticillatum Bail. Berrien and Einmet Counties. 
Euastrum Ehrenb., emend. Ralfs. 
Euastrum abruptum Nordst. Oakland County. 
E. ansatiim fa. Scoltii fa. nob. (PI. 1, F'ig. 1 ) [Prescott and Scott, 
1945. Am. Mid. Nat. 34 : 233. PI. 3. Fig. 2. (E. ansahim fa.)]. 
Forma a planta typica difjerens possessione centralis i>ori 
mucosi, atque inflationis unicae mediae supra isfhmum. Cellula 
105 y. long., 47 y. lat. 
A form diiîering froin the typical by the possession of a 
central mucilage pore and by the presence of a single médian 
swelling above the isthmus. Cell length 105 a, cell width 47 a. 
Marsh along Rt. # 94, north of Manistique, Schoolcraft County, 
Michigan. 
Plate 1 
1. Euastrum ansatum fa. Scoltii fa. nob. 
2. Cosmarium botrytis var. subtumidum fa. Irenee-Marie fa. nob. 
3. Cosmarium taxichondrum var. obsolefumiforme var. nov. 
4. Closterium pronum Bréb. zygospore. 
5. Cosmarium protraclum fa. basigranulatum fa. nov. 
6. Cosmarium ongulare var. ocfangulare var. nov. 
7. Cosmarium botrytis var. tumidum fa. nudum fa. nov. 
8. Slaurastriim quebecense var. ornalum var. nov. 
9. Xanthidium subhasliferum var. johnsonii. fa. smithii fa. nob. 
10. Cosmarium amoeniim Bréb. zygospore. 
