118 PESMTPS OF THE UNITED STATES. 



M. Baileyi, Kali;. Plate XXXVII, fig. 6. 



Cell small, granulate; semicells three lobed ; basal Lobes 

 bipartite, apices obtuse, or finely dentate: terminal lobe much 

 exserted, notched, spreading arms obtuse or bidentate at apices. 



Diameter 75 //.. 



New York, Rhode Island, South Carolina, Florida,' Bailey). 

 Ponds, New Jersey, Pennsylvania. Rather rare. 



M. foliacea, Bailey. Plato XXXVIII. figs. 10, 11. 



Cells subquadrate, smooth; seinicells three lobed; lateral 

 lobes deeply bipartite, and again incised, their margins con- 

 cave, incised-serrate ; end lobe rhomboidal, exserted, angles 

 entire, apes divided !>v a wide, rounded sinus, near the basal 

 margin of which arc two or more tooth-like spines. 



Diameter of cells 80-95 fi. 



Bailey reports this species from Worden's Pond, Rhode 

 Island. I found it quite abundant in Gilder Pond, Mt. 

 Everett, Mass. A singular feature was the union of many cells 

 forming long filaments. In the process of multiplication by 

 division vidi Introduction, p. 17 I, the terminal lobes lap one 

 over the other and thus maintain a hold. The chains of cells 

 collected were evidently mere fragments, or part- broken 

 from longer filaments; thev contained from 1<> to 38 cells. 



The details of the terminal lobe vary somewhat from the 

 form described by Bailey. This species has been found also 

 in Brazil, 8. A. 



M. mii:i< \i \. Bailey. Plate XXXI. figs. 1-7. 



" Semicells divided 1>\ deep Indentations into three trans- 

 verse portions; the basal with three sublinear processes on 



each side, the Others with two oil each side.' 



The division-, in front view, do not diverge, but spread later- 

 ally, in such a manner that the one nearesl the eye, more 

 or less conceals it> companions. 



Diameter 100-125 /.; length 150-200/*. 



Catskill Mountains, Bailey); many localities in Pennsyl- 

 vania, New Jersey, Massachusetts. Not abundant, but widely 

 distributed. 



M. Rabexhorstii, Kirch. Plate LI I. fig. 6. 



Cells of equal length and breadth, divided into three lobed 

 semicells by a deep constriction; the sinuses enlarging out- 



