Some specimens also have an arcuate black band over the forehead from one outer corner of the eye to the other.
Multifoil, mul′ti-foil, adj. having more than five foils or arcuate divisions.
The frustules are curved or arcuate (arcus, a bow) in the side view, oblong and narrowed at the ends in the front view.
Valve narrow, with arcuate dorsal and straight ventral margin, acute at the ends.
Valve linear, arcuate on the dorsal, straight on the ventral side, reflexed at the extremities.
These processes appear at first on one of the arcuate cells in successive order.
These dichotomous processes are nothing more than branches developed from the arcuate, or mother cells.
During all these changes, while the zygospore enlarges, the wall of the arcuate cells becomes coloured brown.
The cell measures one cubic inch, the entrance tunnel being one and one half centimeters long, and arcuate.
When the Clavola of the Antenn grows gradually narrower towards the apex, and is arcuate or incurved so as to resemble a sickle.
