ADDENDUM. 



By a regrettable oversight no mention has been made in the text 

 of the interesting new genus Loxsomopsis, described by Dr. Christ as 

 having been discovered in Costa Rica (Bull, de VHerb. Boissier, 2me 

 sen, tome iv., p. 393, 1904). This rare Fern, still unknown as 

 regards stipe and rhizome, shows a habit like that of Loxsoma, but larger 

 The outline of the leaf, especially at the base of the pinnae, show 

 archaic characters, while the sori correspond in general features to the 

 of Loxsoma; but the sporangia have a lateral dehiscence, and a compl 

 ring composed of very numerous cells. In these details Loxsomo; 

 corresponds to Thyrsopteris, Pending a better knowledge of its characi 

 and especially of its anatomy, it may be accorded a place in 

 neighbourhood of Loxsoma and Thyrsopteris^ about the base of th 

 series of Gradatae (compare p. 655, and Fig. 354). 



