96 CHARACTERS OF TRIBES AND GENERA. 



species, all natives of the West Indies and Tropical 

 America. The principal character which distinguishes it 

 from Plilebodium is the sori being produced on free ex- 

 current veinlets, that rise from the arch formed by the 

 venules between the primary veins, and which character in 

 the greater number of the species is well defined, but in a 

 few species with narrow linear opaque fronds the venation 

 is obscure and not so regular, which is due to the narrow- 

 ness of the fronds ; great confusion exists as regards the 

 synonyms of the species of this genus. 



In Seeman's " Botany of the Herald " I have stated " that 

 the general features of the so-called species of this genus 

 are so much alike that the words used to describe one are 

 in many cases quite applicable to others, the species 

 varying merely in degree as to length, breadth, &c. The 

 differences in the anastomosing of the veins would appear 

 to indicate distinctions, uniformity is not, however, the 

 rule ; fronds of the same individual plant, and even 

 different parts of the same frond, are observed to vary in 

 the more or less branching and anastomosing of the veins ; 

 so that I fear venation is of little value for specific dis- 

 tinctions." It is only by seeing them growing side by 

 side under cultivation that the difference of their appear- 

 ance appears manifest. 



* Fronds simple. 



Sp. C. ensifolium (Willd.) v v.) ; C. angustifolium (Sw.) 

 (vv.) ; C. lucidum (Bory) (v v.) ; C. rigidum, (/. 3m. Ferns, 

 Brit, and For.) ; C. fasciale ( Willd.) (v v.) ; C. repens (Linn.) 

 (v v.) ; C. Phyllitides (Linn.) (v v.) ; C. costatum (Kze.) 

 (v v.) ; (C. nitidum, J. 8m. Ferns, Brit, and For.) ; C. brevi- 

 folium (Link) (v v.) ; C. sphenodes, (Kze.) ; C. immersum, 

 (.7. 8m. Bot. Voy. Herald). 



