368 CHARACTERS OF TRIBES AND GENERA. 



OBS. Presl, in his c< Supplementum Tentaminis Pteri- 

 dographiae," enumerates twenty-eight species of this genus, 

 three of which he characterises under three distinct 

 genera, but which I consider of sectional value only. In 

 the " Synopsis Filicum " the species are reduced to one 

 half of the above number. 



Fronds ovate elliptical or linear, 2 to 10 inches in length, 

 "bearing the fertile simple spikes epigeous. (Ophio- 

 glossum vera.) 



Sp. 0. lusitanicum, Linn, (v v.) ; 0. pedunculosum, 

 Desv. (v v.) ; 0. nudicaule, Linn. ; 0. vulgatum, Linn. 

 (v v.) ; L. reticulatum, Linn, (v v.). 



** Fronds pendulous ; the sterile segments long, ribbon-like, 

 usually dichotomously branched, 2 to 10 or more feet 

 in length. Epiphytal. (Ophioderma, Pr.) 



0. pendulum, Linn, (v v.) ; 0. furcatum, J. Sm. (v v.). 



*** Fronds palmate, pendulous, 6 to 10 indies long, 

 fertile spikes numerous, epiphytal. (Cheiroglassa, Pr.) 



0. palmatum, Linn, (v v.). 



**** Fertile spike, rising direct from the Corm. 

 (Rhizoglossum, Presl.) 



O. Bergianum, Schlecht. 



OBS. This is a curious and rare little plant, a native of 

 the Cape of Good Hope, having the sterile and fertile 

 fronds distinct, not more than half an inch in length, its 

 nearest ally being 0. lusitanicum, a native of the South of 

 Europe, of recent years found in Guernsey. 



