138 DFSMIDS OF THE UNITED STATES. 



Pond, Spring Lake, X. J. 



I found this new species only in one pond, but numerous ; 

 it bears tlie appearance of a relation to a Brazil plant de- 

 scribed by Xordstedt as St. Clepsydra, and also to a Spitz- 

 bergen species by the same author, St. pachyrhynchum. The 

 name applies well to the new form, although only two-thirds 

 the size and proportionately longer ; the sides also of end 

 view, are not "slightly concave," but deeply sinuate. 



SECTION II. 



CYTI0DEB5I GEANTILAB OR VERRTJCOSE. 



.St. maegaeitaceum, Ehrb. Plate LII, figs. 31-35. 



■Semi-cells in front view subelliptic, rough with pearly 

 granules; outer margin convex, produced at each side into 

 a more or less attenuate, short process, having the granules 

 in transverse lines ; blunt and entire at the apex. End view- 

 circular, bordered by from 4-6, rarely 7, short, narrow, ob- 

 tuse, granulate marginal rays. 

 Diameter 30-35 //.- 



Found in all States explored, from Rhode Island to Florida. 



St. steiolatum, Naeg. Plate LXII, figs. 27, 28. 



Small, as broad as long, sinus acute angled ; semi-cells ob- 

 verse reniform ; angles rounded, end concave, transverse 

 striate, five or six strife distinct on each lobe ; end view tri- 

 angular, angles rounded and sides concave ; each lobe trans- 

 versely striate. The strife are series of smaller or larger 

 granules. 



Diameter 22-35 j^. 



Not frequent, but found occasionally in distantly separated 

 localities. New Jersey, Pennsylvania, South Carolina, and 

 other States. 



St. teicoene, Breb. Plate LII, figs. 36, 37, 38. 



Cells rough, with puncta-like grantiles ; semi-cells taper- 

 ing on each side into a short, blunt, mostly entire, process ; 

 end view with three or four blunt angles. 



Diameter 22-28 fj.. 



Not in so many localities, but often numerously clustered 

 together ; Pennsylvania, New Jersey. 



,St. ceenatum, Bailey. Plate LII, figs. 5, 6. 



Semi-ceUs cuneate ; outer margins crenate ; end view with 

 three truncate and crenate angles ; sides concave. 



This species was reported by Bailey to Balfs aa found in 

 Rhode Island. Probably not seen since in this country. 



