38 FRESH-WATER ALG^E OF THE UNITED STATES. 



E. VENTRICOSUM, Lund. Plate LVIII, figs. 1-3. 



Large, twice as long as wide, outline subelliptic, deeply 

 constricted, sinus narrow linear ; semi- cell trilobed, base 

 much dilated, polar lobe short somewhat dilated, incision 

 narrow linear, sides sinuate, two-lobed, superior lobe obtuse 

 tending upward, entire, not bifid in lateral view; basal 

 tumors three, intermediate two, and two in end lobe ; in 

 vertical view elliptic, four undulations on each side ; in 

 lateral view narrowed toward the ends, sides undulate, apex 

 subtruncate and dilated; shows the superior lateral lobule 

 entire. 



Diameter 60-69 ^ ; length 105 p. 



Found this plant frequent in pond, Orange County, near 

 Maitland, Florida. Zygospores not infrequent, as fig. 1. 



E. ORASSTJM, Des. U. S. p. 97, var. SCROBICULATUM, Lund. 



Plate LVIII, figs. 4, 5. 



In outline very nearly the same as the type-form, but 

 differs in having in the middle of the semi -cell four scrobi- 

 culae. Lundell represents only two ; our form has four ; 

 besides these excavations the plant has four papilla-like 

 prominences towards the ends of the semi-cells, which I do 

 not find alluded to; they may give claim for a distinct species. 



Pond, Malaga, New Jersey. 



Genus, MICEASTEEIAS. V. Des. U. S. p. 108. 



M. SPECIOSA, Wolle. Plate LVI, figs. 1, 2. 



Small, somewhat longer than broad, five-lobed ; lateral 

 lobes unequal, the basal pair usually with only half as 

 many divisions as the intermediate ones ; each basal lobe 

 consisting of one, and the intermediate of two lobulets, 

 the angles of each section drawn out into two spine-like 

 points; terminal lobe rather narrow, linear, the end ex- 

 serted and much dilated, usually with three prominent 

 mucros at each angle, center an obtuse angled notch, stand- 

 ing free with a rather wide gap between it and the adjoining 

 lobes ; a series of small spines often observed on the margins 

 of the lobes. 



Diameter 95 yu ; length 110 /*, of specimens from Florida ; 

 diameter 125-150 //; length 155-165 yw, of New Jersey 

 specimens. 



