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The genus Disciseda was proposed by Czerniaiev (1845) for a plant in which the exoperidium had persisted as a disc at the base. As he neither described the relevant microscopical characters nor gave any diagrams, the genus remained obscure and unrecognized for a very long time. Morgan (1892) described the genus Catastoma, characterized by the basal mouth, the capillitium, which consisted of short separate threads, and the apical collarlike remains of the exoperidium. Hollos (1903) dug out the generic name Disciseda and claimed that it was co-generic with Catastoma of Morgan. His labors, however, were not rewarded for a long time, as several leading mycologists preferred to use the very appropriate name Catastoma (basal mouth). Now, however, mycologists have begun to recognize Disciseda as the valid generic name on grounds of priority, even though Lloyd (1904) protested strongly against this tendency. The genus is considered by several workers as curious and unique among the Gasteromycetes in having a basal mouth. Lloyd (1918), however, writes of Catastoma ater that "it is not a true Catastomna, . . . in the 'type idea' with 'mouth down,' but there are several species of Catastoma that will not stand that test." Recently Cunningham (1946) also states that that is not a universal feature and that in Disciseda cervina, D. australis, D. anomala, D. verrucosa, and probably others, the stoma develops apically in the usual manner. Lohwag (1930) finds it difficult to explain the basal mouth morphologically. The explanation offered by him is that the endoperidium at the base is torn from the "Myzelium" whereby a hole or at least a weak spot originates which later wears into an aperture. As most of the species grow wholly or partially buried under the surface of the ground, nothing is known about the early de

1. Vegetative reproduction in Exormotheca tuberifera takes place by means of tubers formed by thickening of the apex or by ventral modified shoots. Growth takes place by means of a single apical cell. 2. Development of the antheridium is like that of other Marchantiales. The receptacle contains a layer of air chambers which open on the outside by simple pores. Cell divisions occur in the venter even before fertilization, and result in the formation of a four-layered calyptra. The early development of the sporophyte shows the octant type of embryo. The apical cap is single-layered, with small elater-like cells attached to it. Dehiscence of the capsule takes place by the detachment of an apical cap and splitting up of the capsule wall into four irregular valves.