Since Fries' day the species has been overlooked although the genus has received more than once attention. Zukal _Hedwigia_, XXXV., p. 335, describes _A. speciosa_ as a new species. This Saccardo writes down, Syll. Fung., VII., p. 399, _S. tubulina_ A. & S., admitting, however, at the same time, that as fine an authority as Raciborsky refuses to call Zukal's species either a stemonite or an amaurochete, thinks it deserving generic appellation of its own. However, _A. speciosa_ Zuk. need not here concern us. Neither in his description nor figures does Zukal at all approach the form we study. His species is not an amaurochete; the size of the spores suggest that, to say nothing of the capillitial structure. In the same volume VII., the distinguished author introduces another amaurochete, _A. minor_ Sacc. & Ellis, _Mich._ II., p. 566. This is American; sent from Utah by our famous pioneer collector Harkness. A specimen is before us: it is a lepidoderma! in shining, scaly armor dressed; vid. under _L. carestianum_. Since the distribution of Washington material, as mentioned, our species reappears at various points in western Europe, points in England, etc., and will no doubt now share, hereafter as a century ago, the habitat so long conceded to the long familiar older type. _B._ STEMONITACEAE Capillitium abundant, springing usually as dissipating branches from all parts of the columella; the sporangia generally definite and distinct, though sometimes closely placed and generally rising from a common hypothallus. =Key to the Genera of the Stemonitaceae= _A._ Fructification aethalioid; capillitium charged with vesicles 1. _Brefeldia_ _B._ Sporangia distinct, or nearly so. _a._ Stipe and columella jet-black. 1. Capillitium so united as to form a surface net 2. _Stemonitis_ 2. Capillitial branch-tips free 3. _Comatricha_ _b._ Stipe and columella whitish; calcareous 4. _Diachaea_ =1. Brefeldia= _Rostafinski_ 1873. _Brefeldia_ Rost., _Versuch_, p. 8. Sporangia occupying in the aethalium several layers, those of the median, and especially of the lowest layers, furnished with columellae which blend beneath; capillitium threads in the lowest layers arising from the columella, in the upper extending radiately between the individual sporangia, and united at the sporangial limits by means of rather large inflated sacs.