New species, notes and key to the aeroaquatic genera Beverwykella and Ramicephala gen. nov.

Two new aeroaquatic fungi, Ramicephala sphaerospora gen. sp. nov. and Beverwykella clathrata sp. nov., are described and illustrated from tropical and subtropical latitudes. B. clathrata, a species similar to B. cerebriformis, deviates from the latter in having a clathrate outermost cell layer instead of tightly appressed cells, a feature unique in Beverwykella. The second species, Ramicephala sphaerospora gen. sp. nov., has a unique combination of features concerning conidial ontogeny and morphology, and is therefore placed in a new genus. The genus most similar to Ramicephala is Beverwykella, from which it differs in having: (1) globose, non-flattened conidia; (2) a large central globose cell giving rise to centrifugally branching, tightly packed chains of cells; and (3) a compact peripheral cell layer, the cells of which are tightly interlocked in a zipper-like form. Similarities of R. sphaerospora to species of Pseudaegerita, Candelabrum and Cristulariella are discussed. Illustrations of and a key to all described species of Ramicephala and Beverwykella are provided.