CHARACTERS OF TRIBES AND GENERA. 173 



to differ chiefly in degrees of length and breadth, the whole 

 presenting but few obvious points of difference of specific 

 value. He also attaches much importance to the different 

 forms of the abortive sporangia (paraphyses), the number 

 of articulations forming the ring, and the form of the 

 sporangia, but much more investigation is wanted before 

 these microscopic characters can be made available for 

 determining species. The following are the principal 

 well-marked species. 



* Sporangia intramarginal Hook. Syn. Fil., t. 6, fig. 56, b. c. 

 Ex. V. scolopendrina (Pteris, 'Bory Haplopteris, Presl ; 

 Tceniopsis, J. Sm.) (v v.) ; V. falcata, Kze. ; Y. Gardneriana, 

 Fee ; Y. stipitata, Kze. ; Y. stricta, Carm. ; Y. lineata, Sw. 

 (v v.) (Tceniopsis, Bedd. F. 8. Ind., t. 54) ; Y. remota, Fee. 



** Sporangia in an extrose slit, margin not involute, 

 Hook. Syn. Fil, t. G,fy. 56 A. 



Y. elongata, Sw. (V. zosterce/olia, Willd) (v v.) ; Y. ensi- 

 forrnis, Sw. 



OBS. In the " Synopsis Filicum " this with eight other 

 species are included as synonyms of V. elongata. V. stricta 

 is a native of Tristan d'Acunha, and in general appearance 

 is similar to V. lineata, but differs in the short sarmen- 

 tum being covered with undulate, crisp squamae, not stiff 

 and filiform as in V. lineata. Specimens collected by 

 Griffiths in Bootan have the same kind of crisp squamas 

 as those from Tristan d'Acunha. 



81. PTEROPSIS, Desv. in part (1827). 



Pteris sp., Linn. 



Vernation uniserial, sarmentum short. Fronds contiguous, 

 simple, linear acuminate, 6 to 18 inches long, rigid, smooth. 



