176 CHARACTERS OF TRIBES AND GENERA. 



Illnst. Schk., Fil., p. 82 ; Fee, Gen. Fil., p. 97, t. 9 B. ; 

 Moore's Ind. Fil., p. 13 A.; Hook., Syn. Fil., t. 6, 

 fig. 51, a. b. 



OBS. This genus represents the simplest state of vena- 

 tion in Ferns, the fronds being so small and narrow that 

 no lateral veins are produced, the whole vascular structure 

 consisting of the mid-rib only. In the typical species of 

 the genus, M. graminea, the sporangia are produced on the 

 face of the mid-rib ; but in an additional species of recent 

 discovery, the sporangia are seated in grooves on each side 

 of the mid-rib, and although this is a very special cha- 

 racter, it nevertheless does not seem to me sufficient to 

 warrant their separation as a distinct genus. 



Sp. M. graminea, Schk., Fil., p. 82, t. 9 ; M. trichoidea, 

 J". 8m. ; M. daresecarpa, Hook., Sp. Fil. 5, t. 287 A. ; 

 M. subfalcata, Hook., Sp. Fil. 5, t. 219 A. ; M. rostrata, 

 Hook., Sp. Fil. 5, t. 287 B. 



OBS. These species are widely distributed, being found 

 in South Africa, Mauritius, Borneo, Philippines, New 

 Hebrides, also in the West Indies and Central America. 



In M. trichoidea the line of the sporangia is interrupted, 

 forming several short sori, each included in a fold of the 

 frond, similar to a sheath, which M. Fee has considered 

 worthy of being characterised as a distinct genus which 

 he has named Vaginularea, but which I do not adopt. 



84. DICLIDOPTERIS, 'Brack. (1854). 

 Monogramma sp. Hook. Sp. FiL 



Vernation uniserial, sarmentum short. Fronds con- 

 tiguous, caespitose, linear, 6 to 12 inches long, narrow, 

 graminoid, flaccid, with a central costa and sub-parallel vein 

 on each side, which are sporangiferous nearly their whole 



