Along the coast.
Pl. [9], Fig. 5.
Meridion Ag. (1824)
(merizo, I divide)
Frustules in zone view cuneate, adnate in circular or spiral fasciæ, at length becoming free. Valve symmetrical with respect to the longitudinal axis, more or less cuneate; costæ and striæ transverse.
Chromatophores numerous, small, elongated, in irregular rows on the zone (Pfitzer).
MERIDION CIRCULARE (GREV.) AG.
Transverse costæ coarse, variable in number and distance apart, sometimes interrupted or indistinct; striæ interstitial, 16 in 10 µ.
In springs and small streams of pure water.
Echinella circularis Grev.