But the involute edges of the pileus are bearded with close hairs.
Involute: ridgeless, with flanking lines, but no keel; soft and rather thick.
Involute, in vernation, 72; rolled inwards from the edges, 97.
The margin of the cap is smooth and turned under at first (involute).
The body is ornamented with carelessly drawn, deeply incised, involute designs.
On the sides of the vessel are engraved figures, consisting of clusters of involute lines, as in the specimen just given.
The lines of the involute are arranged in four groups of two each and occupy an unusually wide belt.
The central circle incloses a perforated circlet, and the involute lines are long and shallow.
These names are given to the curves because the end of a stretched thread unwound from the evolute will describe the involute.
Draw setting tangent from “base circle” of involute, at middle of tooth.