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; striæ divergent in the middle, convergent at the ends, 12 in 10 µ. L. 35 µ. 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 Capitatæ are quite variable. {107}DIVERGENTES PINNULARIA DIVERGENS VAR. ELLIPTICA GRUN. Valve linear, with rounded ends; axial area widened in the middle to a transverse fascia; striæ, 9 in 10 µ, divergent in the middle, convergent at the ends. L. 150 µ. Fresh water. Not common in this locality. Pl. 31, Fig. 13. PINNULARIA CARDINALICULUS CL. Valve linear, with rounded ends; axial area wide, less than one-third the width of the valve, expanded to a transverse fascia; striæ divergent in the middle and slightly convergent at the ends, 9 in 10 µ. L. 97 µ. Blue clay. Pl. 30, Fig. 1. As a rule, the median fissures in Pinnularia are turned inwards on the side of the longer edge of the terminal fissures, but not always. In this specimen the median fissures are turned slightly toward the side of the shorter edge of the terminal fissures. PINNULARIA LEGUMEN EHR. Valve linear, with more or less triundulate margins and broad, capitate ends; axial area less than one-fourth the width of valve, widened in the middle; striæ strongly divergent in the middle and convergent at the ends, 10 in 10 µ. L. 84 µ. Fresh water. May's Landing, N. J. Pl. 30, Fig. 3. PINNULARIA LEGUMEN VAR. ? Valve as in type, but with a transverse fascia; striæ, 10 in 10 µ, curved or bent near the ends. L. 84 µ. This form is not var. florentina Grun. May's Landing, N. J. (with the type). Pl. 30, Fig. 4. PINNULARIA BRÉBISSONII (KUETZ.) CL. Valve linear-elliptical, with rounded ends; axial area narrow, widened into a transverse fascia which is usually broader at the ends; striæ divergent in the middle, convergent at the ends, about 12 in 10 µ. L. 40-60 µ (Cl.). Fresh water. Common. Pl. 29, Fig. 12; Pl. 31, Fig. 11. Variable in outline. PINNULARIA MORMONORUM (GRUN.) Valve linear, with rounded ends; striæ divergent in the middle, convergent at the ends, 10 in 10 µ; axial area rhombic-lanceolate, widened to a fascia usually reaching the border. L. 62 µ. _Navicula mormonorum_ Grun. Common near Willistown, Pa. This form is regarded by Cleve as P. brébissonii, but the axial area appears to distinguish it. The valves are sometimes narrowed in the middle. Pl. 29, Fig. 11. {108}BREVISTRIATÆ PINNULARIA ACROSPHÆRIA (BRÉB.) CL. Valve linear, gibbous in the middle and at the ends; axial area about half the width of the valve; median line with approximate central pores; median area punctate; striæ nearly parallel, radiate at the ends, 9 in 10 µ. L. 32-180 µ (Cl.). Blue clay. Recent, fresh water. Pl. 30, Fig. 7.