Chiloscyphus trapezioides Sande Lac, Ned. Kruidk. Arch. 3: 417. 1854 = Conoscyphus trapezioides (Sande Lac.) Schiffh., Consp. Hep. Arch. Ind. 125. 1898. Type: Java.
This species is reminiscent of Clasmatocolea subg. Clasmatocolea in the dorsally assurgent, adaxially concave, undivided leaves, in the conspicuous underleaves and in the general appearance of the plants. It also resembles Austroscyphus tjwideiensis (Sande Lac.) Schust. in the clasmatocoleoid features just mentioned, plus the similarly positioned armature near the ventral base of leaves. In fact the two taxa were at one time both placed in Conoscyphus by several authors, for example, Schiflfner (1900). Conoscyphus belongs to Geocalycaceae, but differs from all other members of that family in possessing 1) gynoecial bracts and bracteole fused to form a tube that encloses and hides the perianth and 2) rhizoids originating from the underleaf disc ca. 0.25 from its base. In my view these differences unnaturally distend the limits of subfam. Lophocoleoideae, where it traditionally has been placed, and it is preferable to place Conoscyphus in a new, independent subfamily: Geocalycaceae subfamily Conoscyphoideae