CHARACTERS OF TRIBES AND GENERA. 167 



by A. acrosiiclioides and y/. Stelleri, all of wbicli are in the 

 " Species Filicum " considered as represeiiting- one species 

 only. Many other species have been added from time to 

 time to this genus, but, on account of their having a spe- 

 cially well-defined indusium, are now most of them referred 

 to the genera Cheilanthes and /'ellcea, several of which, such 

 as Pellcea marginata and P. angustijolia, have a strong- 

 claim in habit to be associated with Allosorus. Their 

 special indusium however marks them as being distinct, the 

 terminal oblong sori of Allosorus indicates its relationship 

 to be with Oymnogramma. 



Sp. A. crispus, Brrnli. (v v.) ; A. Brunoniana, Wall. ; 

 A, acrostichoides, B. TSr. ; A. Stelleri, Eupr. {Pteris gracilis, 

 Mifjix) ; A. glauca, Gav. [Pellrra lursuta, Hook. Sijn. Fil.). 



Obs. — The last two species are placed under Pdlcea in 

 the " Synopsis Filicum." See observation under Pelltea 

 for my reason for placing- them here. 



77. — Jamesoxia, Hool-. anil Grev. (1831). 

 Hook. Sp. Fil. 



Vernation sarmentose, slender, elong-ating, naked, sub- 

 hypogeous, Fronds short stipate, distant, linear, pinnate, 

 erect, 1 to 1-j foot long, rigid, densely covered with tornen- 

 tose articulate hairs v-hen young ; pinnas numerous 

 subrotund, j to J inch long, coriaceous, short petiolate, 

 generally deflexed, contiguous and imbricate, margin 

 revolute, indusasform. Veins flabellately foi'ked. Sporangia 

 occupying the lower part of the venules, forming short 

 sori, which become confluent into one central sorus, covered 

 with crinoid jointed hairs, and partially hid by the indusas- 

 form margin. 



Type, Pteris imbricata, Gav. 



