264 
W. E. WADE 
Haec varietas a specie tijpica differt possessione verrucarnm in 
apicibus. Semicelînîa a ueriice visa seriem lateralem quattuor 
verrucarum admodum intra ntriunque marginem lateralem 
praebei. Intra seriem primam sériés secondaria in friangulum 
ordinata. Celhila 32 |j. long., cum spinis 38 u lat., isthmus 10.5 a 
laf. 
This variety difîers froin the typical in the possession of 
verrucae on the apices. In vertical view, there is a latéral sériés 
uf four verrucae just within each latéral margin. Within the 
first sériés, there is a secondary sériés forming a triangular 
pattern. Cell lenght 32 a, cell width with spines 38 isthmus 
10.5 In barnyard pool at the end of dirt road north of Harris, 
Menominee County. Michigan. 
This organisai should be compared with S. riigosum Irénée- 
Marie from which it dilîers in the possession of two spines 
which are inserted sub-apically on the angles. S. riigosum has 
short latéral processes which are trifîd at the ends. In addition, 
this variety has (in vertical view) two linear sériés of four ver¬ 
rucae each within each latéral margin whereas S. riigosum 
possesses a group of verrucae in a circular pattern. 
S. aviculüides Grônbl. fa. Michigan specimens from Oakland Coun¬ 
ty hâve more robust and sharply curved spines and are smaller 
than the typical. 
R. bicoronatum Johnson. Calhoun and Oakland Counties. 
.S’, bohlinianum Schinidle fa. The sinus on the Chippewa County 
specimens hâve a less acute apex and the latéral margins (in 
vertical view) hâve more strongly developed granules than the 
typical. 
,S'. boreale West and West. Schoolcraft County. 
6'. brachiatum var. major var, nov. (PI. 2, Fig. 4). 
Haec varietas circa duplo maior quam species tgpica, proces- 
siiiim apicibus Irifidis quadrifidisve magis subdivisis. Cellula 
75 jx long., 75 tj. lat., isthmus 17 u. lat. 
Plate 2 
1. Xanfhidiuni nntUopaeum fa. nuchigonensis fa. nov, 
2. Staurastrnm furcnlnrn var. (aylorii var. nov. 
3. Staurastrum var. pseudopisciforme fa. Irenee-Marie fa. nob. 
4. Staurastrum brachiatum var. major var. nov. 
5. Staurastrum cuspidatum var. maximum var. nov. 
6. Staurastrum cornutum fa. reducium fa. nov. 
7. Staurastrum avicula var. coronulatum var. nov. 
8. Staurastrum prescottii sp. nov, 
9. Staurastrum forficulatiim var. cornuliforme var. nov. 
Sowcff; MNHN Pans] 
