84 DESMIDS OF THE EXITED STATES. 



rough with pearly granules; end view with a constriction 

 between the central inflation and the extremities. 

 Diameter 34-38 ft.; length 25-30 u. 



Sparsely found in ponds of Pennsylvania, New Jersey, New 

 Hampshire, and probably most of the States. 



( '. 81 i:< uknatiwi, EEantzsch. Plate XVIII, figs. 6, 7; Plate 

 XIX. fig. 20. 

 Cells with apices or ends more or less distinctly quadricre- 

 nate, sides with (4-) > crenae; within the margins three or 

 four series of granules ; the swelling near the basal line has 

 usually five short series of granules; viewed from the vertex, 

 elliptic, apices truncate-retuse, sometimes rounded; on the 

 swollen middle are often seen five prominent granules; lateral 

 view, ovate with basal swellings and truncate end-. 

 Diameter 20-26 />.; length 23-36 ,". 



Ponds, and sluggish Btreamlets, Pennsylvania, New Jersey, 

 Massachusetts, Minnesota. 



( '. PROTUBERAN8, Lund. Yar. < . i:.\ MI.AITM, W'nlle. Plate LI, 



figs. 13, 14, 15. 



Cells about one-fifth longer than broad; constriction deep, 

 narrow linear; semicells nearly twice a- wide as long, base 

 straight, sides somewhal diverging from the basal line; superior 

 aneles nearly right, inferior angles obtuse; near the middle 

 of the cell, is a small granulated tumor ; -ecu from the vertex 

 elliptic with a centra] swelling on each side; lateral view 

 nearly spherical : membrane granular. 



Diameter 25-28 fl. 



From a small pond near Minneapolis, .Minn. This desmid 

 is evidently not the same aa found in Sweden and described 

 by Lundell, but it ]> - a the principal feature, the " protu- 

 berans " derived from the excess of the diameter of the end 

 of the semicell over the measure of the base. It diners in 

 the less promineni central inflation, and in having the mem- 

 brane granular, not punctate. Kirchner describes a new 

 specie-, C. pseudoprotuberam, which has no central inflation, 

 no granules nor puncta. 



C. Quasilltjs, Lund. Plate XVII, fig. 13, 14, L5. 



Somewhal longer than broad, constriction deep, sinus linear. 



