82 THE DIATOMACE.E OF PHILADELPHIA AND VICINITY 



De Toni includes Lewis' name under Rhoiconeis trinodis (Wm. Sm.) Grun. Rhoiconeis 

 is achnanthiform, with frustules arcuate, and the species is named by Cleve Achnanthes 

 trinodis (Arnott). Caloneis schumanniana (Grun.) Cl., to which as a variety Cleve unites 

 Lewis' form, appears to resemble it only in the lunate marks. 



Fig. 9 represents a single specimen found in the Pavonia deposit and which I believe 

 to be an abnormal form of C. trinodis, differing only in the degree of inflation and in the 

 larger central area. 



Navicula trinodis var. inflate. Schultze, from Staten Island, is the same form figured 

 by Lewis, who states that certain specimens have produced apices. 



CALONEIS PERMAGNA (BAIL.) CL. 



Valve lanceolate, with produced apices; median line nearly straight; axial area lanceo- 

 late, irregular or slightly unilateral, about half the width of the valve; striae, 9 in 10 n, radi- 

 ate and indistinctly punctate; longitudinal lines double. L. 100-200 ju- 



Pinnularia permagna Bail. 



Common in brackish water. 



PI. 21, Fig. 1. 



CALONEIS PERMAGNA VAR. LEWISIANA N. VAR. 



Valve lanceolate, with undulating sides and sub-cuneate apices; axial area less than 

 one-third the width of the valve; striae radiate, 12 in 10 n, indistinctly punctate; longitudi- 

 nal lines double, closer together than in the type. L. 140 p, 



Lewis illustrates this variety in " New and Rare Species," PL 2, Fig. 11, and states 

 that it is probably Navicula esox Kuetzing. This is an error, as Kuetzing's species is Pin- 

 nularia esox Ehr., a form near P. major. 



Rather common in the Delaware River. 



PI. 21, Fig. 2. 



CALONEIS FORMOSA (GREG.) CL. 



Valve lanceolate, with sub-cuneate apices; axial area one-fourth to one-fifth the width 

 of the valve, somewhat unilateral, dilated in the middle; striae, 12-14 in 10 ju, radiate, punc- 

 tate; longitudinal lines double, distinct. Variable in size and outline. 



Abundant along the shores of the Delaware River. 



PI. 21, Fig. 18. 



CALONEIS BREVIS VAR. VEXANS (GRUN.) CL. 



Valve elliptical-lanceolate; apices obtuse; median fissures distant; axial area narrow; 

 central area large, orbicular; longitudinal lines close together, median. 

 Shark River, N. J. 

 PI. 21, Fig. 5. 



CALONEIS WARDII CL. 



Valve linear, ends cuneate; axial area linear; central area dilated to a stauros reaching 

 the margin; striae parallel, radiate at the ends, 18 in 10 ju; longitudinal lines marginal. 

 Not uncommon in the Delaware River. 

 PL 21, Figs. 6 and 7. 



