They are commonly " lenticular " in shape ( like a biconvex lens ), measuring 1 & ndash; 3 mm in diameter . The color of the peridioles is characteristic of the genera : " Cyathus " has black peridioles, " Nidularia " and " Nidula " have brown peridioles, " Mycocalia " has yellow-to red-brown peridioles, and " Crucibulum " has black peridioles that are surrounded by a whitish membrame called the tunica, which makes them appear white.
