Pl. [16], Fig. 21 (upper valve). Fig. 18, var. ?
COCCONEIS SCUTELLUM VAR. ORNATA GRUN.
Upper valve with linear axial area, and transverse and radiating punctate lines which end at the border in a double row of finer puncta; lower valve with much finer puncta, a lanceolate axial area and a loculiferous rim.
Atlantic City. Common.
Pl. [16], Figs. 27 and 28.
The forms along the coast vary infinitely both in size and appearance. The var. ornata is very abundant along the entire coast. In any gathering, valves are found with or without the rim which is frequently seen detached. The upper valve is sometimes without the double row of puncta. Fig. 21 represents an upper valve more coarsely punctate than usually occurs. Very many intermediate forms might be noticed.
COCCONEIS PEDICULUS EHR.
Valves rhombic-elliptical, very convex, somewhat asymmetrical; the upper valve with a linear pseudoraphe, sometimes widened near the ends, and slightly radiating, finely punctate striæ; lower valve with narrow, axial area and finely punctate, radiating striæ.
Not uncommon in fresh water. Abundant in a ditch at Paoli, Pa.
Pl. [16], Figs. 23 and 24.