Valve suborbicular or triangular, with short, truncate processes. Surface with fine puncta about 13 in 10 µ radiating in straight or curved lines toward the circumference and with fine spurs at intervals. Nearer one process than the other, and about half way between centre and circumference, are two small spines, one on each side. Quite variable in size. Blue clay. Common along the coast. Pl. 7, Fig. 9. Fig. 10 (magnification about 260 diameters only) illustrates sporangial frustules discovered by Mr. T. Chalkley Palmer at Reedy Island, Delaware River. In frustules having a cylindrical form, the endochrome lines the cell-walls in the form of granules which become congregated toward the centre in the sporangia. BIDDULPHIA ALTERNANS (BAIL.) V. H. Valve triangular or, rarely, quadrangular, with sides straight or slightly concave, usually unequal. Angles obtuse, separated from the centre by costate lines. Surface with puncta of irregular shape, large at the centre, with smaller puncta interspersed. In many valves several lines appearing like costæ extend inward from the border in various directions. Angles with small puncta in transverse and longitudinal rows. _Triceratium alternans_ Bail. Blue clay. Along the coast. Pl. 6, Fig. 7 and probably Fig. 8. BIDDULPHIA RETICULUM (EHR.) Frustule quadrangular. Valve triangular with straight or concave sides and rounded angles. Surface convex at the centre and angles. Markings of unequal size, mostly larger at the centre, scattered; at the angles, small puncta in longitudinal rows. _Triceratium sculptum_ Shad. _Triceratium punctatum_ Br. _Triceratium obtusum_ Br. For explanation of the synonymy see "Biddulphoid Forms of N. A. Diat.," Proc. Acad. Nat. Sci., 1900, p. 724. Blue clay. Along the coast. Pl. 6, Fig. 5. (_c_) ANAULEÆ EUNOTOGRAMMA WEISSE (1854) (eu, well, noton, a back, and gramma) Frustule quadrangular. Valve elliptical or lunate divided by septa which constrict the margin. Surface flat with punctate markings. EUNOTOGRAMMA LÆVE GRUN. Valve lunate with obtuse ends. Septa, from four to eleven or more. Surface with puncta in transverse and longitudinal rows, sometimes indistinct and scattered. Shark River. Rare. More common southward. Fossil at Buckshutem, N. J. Pl. 7, Fig. 11, and Pl. 10, Fig. 15. I am unable to distinguish between E. læve and E. debile, as intermediate forms occur. {34}TERPSINOË EHR. (terpsinoos, gladdening?) Frustules quadrangular, adnate in filaments, usually free. Valve elliptical or triangular, with undulating sides divided by septa into three or more sections. TERPSINOË AMERICANA (BAIL.) RALFS Valve lobed at each end or angle. Central space rounded, hyaline. Surface with fine puncta in radiating lines. Blue clay. Not common. Pl. 6, Fig. 10. TERPSINOË NOVÆ-CÆSAREÆ BOYER