THE DIATOMACE^ OF PHILADELPHIA AND VICINITY 85 



DIPLONEIS CRABRO VAR. PANDURA (BREB.) CL. 



Valve constricted, segments tongue-shaped; central nodule small; horns narrow, 

 nearly parallel, with a row of large puncta; costse, 4 in 10 /u, convergent in the middle, radi- 

 ating at the ends, alternating with a double row of puncta, 11 in 10 /i. 



Pavonia, N. J. (artesian well). 



PI. 20, Fig. 4. 



DIPLONEIS CRABRO VAR. EXPLETA (A. S.) CL. 



Valve slightly constricted, segments tongue-shaped; costse robust, 5 or 6 in 10 /u, alter- 

 nating with double rows of rather coarse puncta. L. 56 n. 

 Port Penn, Delaware River. 

 PI. 20, Fig. 15. 



DIPLONEIS CRABRO VAR. PANDURELLA CL.? 



Valve constricted, the lobes elliptical ; central nodule large, with horns parallel in the 

 middle, convergent at the ends; furrows wide, with faint costse; no lunula; costae parallel 

 in the middle, radiate at the ends, 9 in 10 /*, alternating with very fine double rows of 

 puncta (not shown in the figure). L. 65 /*. 



Blue clay. 



PI. 20, Fig. 13. 



DIPLONEIS CRABRO VAR.? 



Valve constricted, segments elliptical; costse, 8 in 10 n, converging in the middle, 

 radiating at the ends; horns narrow; furrows wide, costate; lunulse indistinct. L. 75 ju. 

 Resembles var. pandurella except in the convergence of the costse and in the lunula. 

 Squan River. Marine. 

 PI. 20, Fig. 9. 



DIPLONEIS FUSCA VAR. DELICATA (A. S.) CL. 



Valve elliptical ; furrows broad, crossed with rows of faint costse and alveoli ; costse, 6 

 or 7 in 10 M; alveoli, 10 in 10 /*, in short, irregular, longitudinal rows. L. 84 j. 

 Port Penn, Delaware River. 

 PL 20, Fig. 11. 



DIPLONEIS GRUENDLERI (A. S.) CL. 



Valve constricted, segments tongue-shaped, often unequal; horns broad, divergent 

 in the middle; furrows narrow; costse transverse, crossed by from 3 to 7 longitudinal costse, 

 interrupted in the middle at the border. 



Blue clay. 



PI. 20, Figs. 7 and 8. 



DIPLONEIS PUELLA (SCHTJM.) CL. 



Valve elliptical, sometimes orbicular; furrows very narrow; striae, 20 in 10 n, indistinct. 

 L. 15 /* 



Diploneis elliptica var. minutissima Grun. 

 Shark River, N. J. Brackish. 

 PI. 20, Fig. 12. 



DIPLONEIS EXCENTRICA, N. SP. 



Valve elliptical; central nodule quadrate; furrows of the same width throughout, 

 nearly parallel; costse radiating toward the ends, 10 in 10 /u, indistinct on the furrows, 

 alternating with alveoli, 7 in 10 M, in irregular, longitudinal lines. One side of the valve is 

 one and a half times the width of the other. L. 49 pi. 



