Pl. 8, Figs. 17 and 18. GRAMMATOPHORA MARINA VAR. SUBTILISSIMA (BAIL.) V. H. Valve linear, slightly constricted near the smooth apices. Septum undulated near its origin and then straight, incrassate at the end. Puncta in quincunx very subtle, 34-36 in 10 µ. _Grammatophora subtilissima_ Bail. Grammatophora oceanica var. subtilissima (Bail.) V. H., according to De Toni. G. marina and G. oceanica are united by some authors; the latter has more subtle striæ. Along the coast. Pl. 8, Figs. 13 and 14. GRAMMATOPHORA SERPENTINA RALFS Valve linear-elliptical, long, measuring to 150 µ (De Toni); smooth at the apices. Septum with numerous undulations and hooked at the apex. Puncta in quincunx, 17 in 10 µ. Along the coast. Pl. 8, Fig. 21. GRAMMATOPHORA ANGULOSA VAR. HAMULIFERA (KUETZ.) GRUN. Frustule nearly quadrate; valve with rounded but not smooth apices. Septum bent into a sharp angle near its origin and ending in a broad hook. Puncta in transverse rows, 14 in 10 µ. Along the coast. Pl. 8, Figs. 15 and 16. GRAMMATOPHORA ISLANDICA EHR. Frustule oblong; valve elliptical-lanceolate. Septum robust with several undulations and hooked at the end. Pseudoraphe distinct; transverse rows of puncta, 10 in 10 µ. Reported by Kuetzing in the Atlantic Ocean and by Kain at Belmar, N. J. I have not found it on our coast and I believe, in some cases, it has been confused with _G. angulosa_ var. _hamulifera_. The figure is drawn from an Iceland form in H. L. Smith T. S., 186. Pl. 8, Figs. 19 and 20. STRIATELLA AG. (1832) (dim. of stria, referring to the lines on the frustule) Frustules tabulate, adnate in short, stipitate filaments, scarcely siliceous, divided into partitions, septate or partly so at alternate ends. {38}STRIATELLA UNIPUNCTATA (LYNG.) AG. Frustules with numerous bent septa extending the entire length. Valve lanceolate, somewhat unsymmetrical, subtly punctate, with pseudoraphe quite distinct. "The specific name is derived from the appearance of the endochrome which in the living specimen is invariably collected in a central mass with slender threads radiating in all directions toward the cell-wall" (Wm. Sm.). Pyrenoids cuneate, in the centre of the endochrome, numerous. Long Island Sound and along the coast. Pl. 8, Figs. 22 and 23. STRIATELLA INTERRUPTA (EHR.) HEIB. Frustules quadrangular, with robust alternate septa extending to the middle. Puncta in quincunx, 22 in 10 µ. _Tessella interrupta_ Ehr. Very rare along the coast. Pl. 8, Fig. 24. (From a form found at Stonington, Conn.) ATTHEYA WEST (1860) (named after Thomas Atthey) Frustules quadrangular, tabulate, with numerous annuli. Valve elliptical-lanceolate, with a pseudoraphe and a central punctum. Extending from each end is a strong spine half as long as the valve. ATTHEYA DECORA WEST The only species. Diagnosis of the genus. The valves are imperfectly siliceous, scarcely visible in balsam. Very local. Abundant at Shark River, N. J. Pl. 8, Fig. 25.