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 Herb. Botssier, 2me 
ser, tome iv, p. 393, 1904). This rare Fern, still unknown as 
regards stipe and rhizome, shows a habit like that of Zoxsoma, but larger. 
The outline of the leaf, especially at the base of the pinnae, shows 
archaic characters, while the sori correspond in general features to those 
of Zoxsoma; but the sporangia have a lateral dehiscence, and a complete 
ring composed of very numerous cells. In these details Loxsomopszs 
corresponds to Zhyrsopterts. Pending a better knowledge of its characters 
and especially of its anatomy, it may be accorded a place in the 
neighbourhood of Loxsoma and Thyrsopterts, about the base of the 
series of Gradatae (compare p. 655, and Fig. 354). 
