DESMIDS FLORA OF MICHIGAN 
263 
Gogebic County is assigned here as a form with shorter pro¬ 
cesses, less convex dorsal margins in front view and straight 
latéral margins in vertical view. 
S. anatiniwi var. truncatum West. Schoolcraft County. 
S. anchora West and West. Barry and Oakland Counties. 
S. (inkijroides var. pentacladiini G. M. Smith. Barry County. 
S. arcuatiim var. pseiidopiscifonne fa. Irenee-Marie fa. nob. (PI. 2, 
Fig. 3). {Straurastnim pseudopisciforme Irénée-Marie non Eichl. 
and Hacib., 1938, Flor. Desm. de la Rég. Mont.: 330. PI. 55, 
Fig. U). 
Haec varietas a planta typica dilfert processibiis vix proiectis 
ac vix diveryentibus, tribus seriebus concentricis graniiloniin 
ornatis, difjert necnon 3-6 spinis parvis processus verticilli api- 
calis terminantibiis. 
Cellula sine spinis 27-30 u. long., cum spinis .U-42 u long., sine 
spinis 25-30 .a lut., cum spinis 3k-k2 y. lut. Istbmus 8-11.7 u. lut. 
This variety dilîers from lhe typical by tlie only slightly 
projected and only slightly divergent processes whicli are orna- 
mented with three tranverse séries of granules, and by the 3-6 
small spines terminating the apical whorl processes. 
Cell length without sjiines 27-30 y., cell length with spines 
34-42 U, cell width without spines 25-30 y., cell width with spines 
34-42 y-, isthnuis 8-11.7 y.. Crâne Lake, north of Manistique on 
Route M-94, Schoolcraft County. Michigan. 
S’, pseudopisciforme Eichl. and Racib. has been assigned as a 
variety of S. arcuaium Nordst. Thus Irénée-Marie’s (1938) 
report of an organism idcntified as S. pseudopisciforme miist be 
considered as a variety of S. arciiatum. An examination of the 
original illustration of Eichler and Raciborski (1893), however 
revcals an entirely ditïerent plant from the one shown by 
Irénée-Marie. The original figures show a lower whorl of 
narrow diverging processes which are terminated by two stout, 
divergent spines. The bases of the processes hâve a few granules. 
In the upper whorl, the processes are bi-spinate at the apices. 
Speciinens from Schoolcraft County are very similar to those 
illustratcd by Irénée-Marie (1938). The processes are very sligh¬ 
tly projected. only very slightly divergent and ornamented with 
three tranverse sériés of granules. The apical whorl processes 
are terminated by 3-6 small spines. The writer believes that these 
tw'o organisnis are so nearly alike that they should be assigned a 
new form nanie. 
S. aviciila var. subarcuatum (Wolle) West. Barry, Delta, Eminet, 
Houghton, Presque Isle, Roscommon and Washtenaw Counties. 
S. avicula var. coronulatum var. nov. (PI. 2, Fig. 7). 
