CHARACTERS OF TRIBES AND GENERA. 169 



Jamesonia cannot be considered otherwise than a truly 

 aberrant genus ; according- to my view its nearest relation- 

 ship appears to be with Oymnogramma, and its revolute 

 indusaaform margin seems to warrant its being placed in the 

 present section. 



78.— Plecosoeds, Fee (1851). 

 Gheilanihes sp. Hook. 8p. Fil. 



Vernation fasciculate, erect, aoaulose. Fronds stipate, 

 lanceolate, li to 3 feet high, bi-tripinnatifid, densely pilo- 

 squamose ; pinnis numerous, contiguous, sessile, linear 

 lanceolate, -1 to G inches long ; pinnules oblong lanceolate, 

 I to I of an inch long, laoiniately lobed, lobes small, 

 margins inflexed, forming- cucullate scariose universal 

 indu.sia. Veins forked, obscure ; venules free. Sporangia 

 sub-terminal. iSori punctiform, contiguous, included under 

 the cucullate indusia, ultimately confluent. 



Type. Cheilanthes speciosissima, A. Braun. 



Illust. Fee Gen. Fil., t. 13, fig. 1; Moore Ind. Fil., 

 p. 28, A. 



Obs. — This genus is founded on a solitary species, a 

 native of Mexico. It is a Fern of peculiar aspect, pos- 

 sessing characters that makes its relationship doubtful. 

 The multifid and squamose fronds point towards Notho- 

 chlixna and Clieilanthes, but from which it differs in having 

 lateral, intramarginal sori, which are involved in numerous 

 hair-like scales, and which, being included under the indu- 

 siBform marg-in, seems to indicate its affinity with Allosorus ; 

 under these circumstances I deem it best to place it in the 

 present section in proximity to Jamesonia. 



Sp. P. speciosissima, il/oore (P . mexicana, Fee ; Cheilanthes 

 speciosissima, Kze. Analct., t. 23). 



