PINNULARIA ACROSPHÆRIA VAR. TURGIDULA GRUN. ? Valve strongly gibbous in the middle; ends rounded; striæ, 12-13 in 10 µ. L. 54 µ. Blue clay, Gloucester, N. J., artesian well. Pl. 30, Fig. 8. PINNULARIA BLANDITA N. SP. Valve linear, gibbous in the middle, and with rounded ends; striæ radiate in the middle, convergent at the ends, 13 in 10 µ; axial area about one-fourth the width of the valve, widened in the middle; median line with small semicircular terminal fissures. L. 65 µ. Pavonia, N. J., artesian well. Rare. Pl. 30, Fig. 25. PINNULARIA PARVA (EHR.) CL. VAR. ? Valve linear, tapering to the subcapitate ends; axial area broad, lanceolate; median line with approximate central pores and semicircular terminal fissures; striæ slightly divergent in the middle and convergent at the ends, 12 in 10 µ. L. 58 µ. Differs from the type in having finer striæ. Atco, N. J. Pl. 30, Fig. 14. PINNULARIA NODOSA FORMA CAPITATA CL. Valve triundulate, with capitate ends; axial area about one-fourth the width of valve; striæ parallel, convergent at the ends, 10 in 10 µ, sometimes interrupted in the middle. L. 47 µ. Fresh water. Common. Pl. 30, Figs. 15 and 19. PINNULARIA POLYONCA (BRÉB.) LEWIS Valve with triundulate margins, more inflated in the middle, with capitate ends; axial area very broad; striæ marginal, short, 9 in 10 µ, divergent in the middle, convergent at the ends. L. 97 µ. Kirkwood Pond, N. J. Pl. 30, Fig. 21. The description of Kuetzing (Species Algarum, p. 85), where he states that the margins are "triundulate, the median inflation larger, apices rounded-capitate," appears to sufficiently distinguish this species, which I believe to be the same as Brun's Navicula peripunctata, except that the form figured (Espèces Nouvelles, Pl. 16, Fig. 11) is interrupted in the middle, a common variation in these forms. Cleve makes Navicula polyonca Bréb. equal Pinnularia mesolepta, but at the same time he considers Lewis' form and also Brun's as equivalent to Navicula formica Ehr., and calls it Pinnularia nodosa var. formica Ehr. P. mesolepta has a narrower area than nodosa. I adhere to Lewis' identification, as in any case it is the form here figured and is nearly, if not quite, the same as Brun's species. {109}DISTANTES PINNULARIA LATA (BRÉB.) WM. SM. Valve linear-elliptical, broad; axial area broad, widened in the middle; striæ slightly radiate in the middle, 3 in 10 µ; median line oblique, the terminal fissures hook-shaped. L. 86 µ. Blue clay. Not uncommon. Pl. 30, Fig. 23. PINNULARIA BOREALIS EHR. Valve linear, with rounded or sub-truncate ends; axial area about one-fourth the width of the valve, widened in the middle; median line with large hook-shaped terminal fissures; striæ, 4 or 5 in 10 µ. L. 54 µ. Blue clay. Occasional in fresh water in a smaller form. Specimens occur intermediate between P. lata and P. borealis. Pl. 30, Fig. 22; Pl. 31, Fig. 12. PINNULARIA BOREALIS VAR. SCALARIS (EHR.) CL.