APPENDIX. No. V. 461 



parts of the coast and to India, appears to connect in some respects Saccharum 

 with Panicum. 



The remarks I have to make qn the Acotyledonou^ Plants from Congo, relate 

 entirely to 



FILICES, of which there are twenty-two species in the collection. The 

 far greater part of these are new, but all of them are referable to well esta- 

 bUshed genera, particularly to Nephrodium, Asplenium, Pteris, and Polypo- 

 diura. There are also among them two new species of Adiantum, a genus of 

 ■which no species had been before obsened on this line of coast. Trichomants 

 and Hymcnophylliim axe wanting in the collection, and these genera, which 

 seem to require constant shade and humidity, are very rare in equinoctial 

 Africa. Of Osmundacece, the herbarium contains only one plant, which is a 

 new species of Lygodium, and the first of that genus that has been noticed 

 from the continent of Africa. 



Among the few species common to other countries, the most remarkable is 

 Gleichenia Hermann!,* which I have compared and found to agree with 

 specimens from the continent of India, from Ceylon, New Holland, and even 

 from the Island of St. Vincent. 



Acrostichitvi stemai-'ia of M. de Beauvois,-|- which hardly differs from A. alci- 

 corneof New Holland, and of several of the islands of the Malayan Archipelago, 

 was also observed ; and Acrostichum aureum, which agrees with specimens 

 from equintjctial America, was found growing in plenty among the mangroves 

 near the mouth of the river. 



I have formerly observed that tlie number of FUices, unlike that of the 

 other Cryptogamous orders, (Lycopodineas excepted,) is greatest in the lower 

 latitudes ; and, as I then supposed, near or somewhat beyond the tropics. 

 The latter part of this statement, however, is not altogether correct ; the 

 maximum of the order, both in absolute and relative number of species, being 

 more probably within the tropics, though at considerable heights. 



The degree of latitude alone being given, no judgment can be formed 

 respecting tlie proportion of Fihces: for besides a temperature somewhat 



* Prodr. Flor. JVov. BoU. \,p. IGl. Merlensia dichotoma fVilld. Sp. PI. 5, p. 7K 

 I Flore d'Ouare \,p. 2, t. 2. 



