130 DESMIDS OF THE UNITED STATES. 



minal lobes with two slender transverse bidentate projec- 

 tions." 

 Diameter 110-120 /*. 



Found good specimens in collections made in lakes, Winter 

 Park, Florida. Besides the typical form also a variety which 

 has the ends of the basal lobes deeply bisected, to nearly half 

 the length. 



M. BAILEYI, Ealfs. Plate XLI, fig. 6. 



Cells small, granulate ; semi-cells three lobed ; basal lobes 

 bipartite, apices obtuse, or finely dentate; terminal lobe 

 much exserted, notched, spreading arms obtuse or bidentate 

 at apices. 



Diameter 75 yu. 



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

 Ponds, New Jersey, Pennsylvania. Rather rare. 



M. FOLIACEA, Bailey. Plate XLIV, figs. 10, 11. 



Cells subquadrate, smooth ; semi-cells three lobed ; lateral 

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

 cave, iiicised-serrate ; end lobe rhoinboidal, exserted, angles 

 entire, apex divided by a wide, rounded sinus, near the 

 basal margin of which are two or more tooth-like spines. 



Diameter of cell 80-95 p. 



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 (vide Introduction, p. 27), the terminal lobes lap one 

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

 collected were evidently mere fragments, or parts broken from 

 longer filaments ; they contained from 10 to 38 cells. 



The details of the terminal lobe vary somewhat from the 

 form described by Bailey. This species has been found also 

 in Florida and in Brazil, S. A. 



M. MURICATA, Bailey. Plate XXXV, figs. 4 7. 



"Semi-cells divided by deep indentations into three trans- 

 verse portions ; the basal with three sublinear processes on 

 each side, the others with two on each side." 



The divisions, in front view, do not diverge, but spread 

 laterally, in such a manner that the one nearest the eye more 

 or less conceals its companions. 



Diameter 100-125 f*. ; length 150-200 p. 



Catskill Mountains, (Bailey); many localities in Pennsyl- 

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

 distributed. 



