Trichomanes L. 



Subgenus Didymoglossum Desvaux. 



Among the Hymenophyllaceae from Madagascar received 

 from S. A. I. JRoland Bonaparte are a séries of species 

 belonging to the section Microgonium of the subgenus 

 Didymoglossum. The right détermination of them is rather 

 difficult and most authors having greatly misunderstood 

 them. The monographer of the family, Van den Bosch, 

 whose most valuable and exact works hâve been too much 

 overlooked by pteridologists, made several African species 

 of the group, which I, in Index Filicum, referred to three 

 species: T. cuspidatum, T. erosum and T. Lenormandi, mak- 

 iug falsely the latter identical with T. Kirkii Hook. Since 

 the time of V. D. BosCH the following species hâve been 

 described: T. Barklyamim Baker from Mauritius, T. Hilde- 

 hrandtii Kuhn and T. microphyllum Gies. (= T. Giesenhagenii 

 C. Chr.), both from the Comoros. 



In 1913 Mr. W. A. Goddijn, began the publication of 

 a new édition of V. D. Bosch's Synopsis accompanied by 

 the original drawings of V. D. BosCH illustrating essential 

 characters of his proposed species. (Mededeelingen van Rijk's 

 Herbarium. Leiden n° 17, 1918). Till now only the first part 

 bas been issued, still it is to be hoped that the publication 

 will be continued. The published part contains fortunately 

 the species of the group Microgonium and by consulting 

 this work I was enabled to détermine the spécimens at 

 hand with certainty. Only in one instance I am doubtful, 

 whether the name T. Lenormandi is rightly applied to the 

 species so named below, or the name ought to be applied 

 to the species described below as T. pygmœum. 



AU the species dealt with below belong to § Microgo- 

 nium that is characterized by its glabrous fronds, while the 



