A New Species of Cryptothallus from Costa Rica

Cryptothallus hirsutus is described as a new species from Costa Rica differing from C. mirabilis of oceanic northwestern Europe in its indehiscent capsules with no elaterophore and spores not coherent as tetrads. The faintly green gametophytes are particularly hairy and rhizoidal on both surfaces. The wide disjunction of these two underground species, surely disadvantaged in spore dispersal, supports recognition at a specific level. Curiously non-green, much branched thalli found underground on the Cerro de la Muerte in Costa Rica were presumed to be gametophytes of a Ly- copodium, sporophytes of which were associated with them. Joseph Beitel, who was present at the time of discovery, recognized them as a Crypto- thallus, and on closer examination, they indeed proved to be a thallose liverwort of the Metzgeri- ales similar to Aneura in having fleshy thalli and shoot calyptrae that enlarge and protect sporophytes throughout their growth and development. In sub- terranean habitat, pale, coralloid aspect, and struc- ture, the plants (Figs. 1, 3-4) greatly resemble