112 M, Montagne on the Podaxinese. 



Gp'ophraffmium results from the dismembering of the genus 

 Montagnea, founded by Fries, ' Genera Hjonenomycetum/ p. 7, 

 on two fungi which grow on the shores of Maguelone, in the en- 

 virons of Montpeher, one of which had received the name of 

 Agaricus ai-enarius from M. DeCandolle, the other that o^Agaricus 

 ocreatus from M. Dehle. The continued study which I have made 

 of the second of these species, subsccjucntly found near Bona and 

 brought in all stages of evolution by Captain Durieu, jNIember of 

 the African Commission, has proved to me that these two fungi, 

 although similar and apparently related, do not belong to the 

 same family. A very young individual of Gyrophragmium Du- 

 nalii showed indeed in the clearest manner, that what had been 

 taken for the pileus of an Agaric was the superior half of a pe~ 

 ridium, the inferior half of which is represented by an ample 

 volva surrounding the stem, and that the supposed leaflets or 

 lamellse were only processes, or rather partitions emanating from 

 all the points of the pileiform portion of the peridium. The fol- 

 lomng are the characters upon which this curious genus is esta- 

 blished : — 



Receptaculum stipatum. Peridium primo turbinatum, dein medio 

 orbiculatim ruptum siiperne pileiforme cum stipite centrali ad apicem 

 usque producto, volva ampla (quae nihil aliud nisi pars peridii infe- 

 rior) instructo continuum. Capillitium in dissepimenta contextum 

 lamelliformia subparallela e peridii toto hemisphserio descendentia, a 

 stipite distantia, in piano ramosa, non autem anastomosantia, sinuosa, 

 plicato-crispata adeoque densata ut sibi cohserere videantur, primo 

 lenta olivacea, tandem exarescentiafragilissima, nigra, subtus libera, 

 labyrinthiformia. Flocci liberi nuUi. Sporse globosae, pedicellatae, 

 dissepimentis affixae. Contextus peridii stipitisque fibrosus in disse- 

 pimenta continuatus. Fungi arescentes, persistentes, h&hitn Agarico 

 vel Boleto similes, specie volvati aut annulati, stipitati, in arenosis 

 maritimis Africce borealis et Gallice australis hucusque obvii. 



The genus Gyroplwagmium differs from Pohjplocium, Berk., on 

 the one hand by the form and the rigidity of its partitions, and on 

 the other by the absence of free filaments intermixed with the 

 sporules, filaments which are found in the latter genus. Just as 

 in Secotiiim its sporules are fLxed by a short pedicel to the walls of 

 the compartments, but these compartments, which are free in Gy- 

 rophragmium, form a spongy tissue in the other genus by their 

 frequent anastomoses. 



Considered according to the degree of their structui-e, the ge- 

 nera of the tribe Podaxineoe may be arranged as follows : Caulo- 

 glossum, Cycloderma, Podaxon, Secotium, Polyplocium and Gyro- 

 phragmium. As Secotium is the form of transition from Po- 

 daxon to Polyplocium, so the latter evidently constitutes a passage 

 between the first of these genera and Gyrophragmium. I have 



