ox GKN'ERA A\D SPECIES. 69 



instauce, in C. arborea and C. serra, tlio fronds are lermiiial, 

 f'ormmg the characteristic corona common to tree Ferns. 

 When mature they separate from the stem, leaving a clean 

 scar similar to Eremobrya, thus diflerino- from the adherent 

 vernation characteristic of the mass of the species of the 

 tribe Ci/alhea ; but as they agree in all the essential 

 characters as regards the nature of their fronds and fructi- 

 iication, it is tliereforc necessaiy to obtain more evidence 

 as to the mode of evolution ami struetare of these tree 

 Ferns before any satisfaetorj- conclusion can bo arrived at, 

 as to enable us to view it as a special character to mark 

 distinct genera.* 



This now leads me to notice another iamily of Perns 

 — namely, Marattiaccw, which ha^"e a very distinct and 

 special habit from other Ferns, and are well marked by the 

 sporangia being destitute of a ring. The evolution of the 

 frond is terminal and articulate to the caudex, as in Cijatliea 

 arborea above noticed, but difi'ers in the fronds rising 

 from between two stipuliform appendages in the form of 

 a socket, analogous to the stipules of plitenogamous plants. 

 The speciality of this group of Ferns leads me to view it 

 as constituting a distinct division, which T have named 

 Scaphobrya. 



This division comprehends but a small number of specie.? 

 as compared with Kremobrya and Destnobrj-a, the number 

 probably not exceeding thirty or forty, the principal pai-t 

 of which are included under the genera Maratlia, Angi- 

 opteris and Danea. 



* Since the above was written, a valuable lacriioir '' Ou tlie .Structure 

 and Formation of the Stems of the Tree Ferns of India," has been 

 published in the thirtieth volume of the Transactions of the Linnean 

 Society, 1874, by Mr. J. Scott, Curator of the Botanic Gardens, 

 Calcutta. It consists of thirty-nine pages nf letterpress, accompanied 

 by eighteen plates. 



