106 THE DIATOMACE.E OF PHILADELPHIA AND VICINITY 



PINNULARIA SUBCAPITATA VAR. PAUCISTRIATA GRUN. 



Valve linear-elliptical, with rounded ends; axial area gradually widened into a broad, 

 transverse fascia; striae divergent in the middle, convergent at the ends, 11-12 in 10 p. 

 L. 47 M . 



Fresh water. 



PI. 30, Fig. 16. 



PINNULARIA TERMES (EHR.) A. S. 



Valve linear, with concave margins and rostrate-capitate ends; axial area narrow, 

 widened in the middle to an orbicular or sub-quadrate space ; striae divergent in the middle, 

 scarcely, if at all, convergent at the ends, 10 in 10 ju. 



Pensauken, N. J., artesian well. 



PL 29, Fig. 17. 



This is, I believe, the form figured by Schmidt (Atlas, PL 45, Fig. 67). Cleve refers 

 it to Pinnularia interrupta forma biceps, in which the central space is rhomboid. 



PINNULARIA TERMES VAR. STAURONEIFORMIS V. H. 



Valve linear, with concave margins and capitate-rostrate ends; axial area narrow, 

 widened into a rhomboidal fascia, reaching the margin; striae, 10 in 10 /i, divergent in the 

 middle, convergent at the ends. 



Pinnularia interrupta forma stauroneiformis Cl. 



Fresh water. 



PL 29, Fig. 14. 



PINNULARIA APPENDICULATA (AG.) CL. 



Valve linear, with subcapitate ends; axial area narrow; central area a transverse 

 fascia; striae divergent in the middle, convergent at the ends, 16 in 10 p. L. 43 /it- 

 Fresh water. Marl pits, Lenola, N. J. (Palmer). 

 PL 29, Fig. 18. 



PINNULARIA BRAUNII GRUN. 



Valve linear-lanceolate, with capitate ends; axial area gradually widened toward the 

 middle and expanded into a fascia reaching the margin; striae divergent in the middle, con- 

 vergent at the ends, 11 in 10 ju- L- 52 p. 



Pensauken, N. J., artesian well. 



PL 29, Fig. 16. 



PINNULARIA MICROSTAURON (EHR.) CL. 



Valve convex, linear, tapering to sub-cuneate or sub-rostrate ends; axial area very 

 narrow; central area a broad fascia; strire divergent in the middle, convergent at the ends, 

 12 in 10 M . L. 35 M . 



Pavonia, N. J., artesian well. 



PL 29, Fig. 19. 



This form does not exactly correspond to Cleve's diagnosis, as the ends are not broad. 

 All species in the group Capitatee are quite variable. 



