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 Gymnogramma, and its revolute 
indussform margin seems to warrant its being placed in the 
present section. 
/8.—PnuEcosoRus, Fée (1851). 
Cheilanthes sp. Hook. Sp. Fil. 
Vernation fasciculate, erect, acaulose.  Fronds stipate, 
lanceolate, 1} to 3 feet high, bi-tripinnatifid, densely pilo- 
Squamose; pinnz numerous, contiguous, sessile, linear 
lanceolate, 4 to 6 inches long ; pinnules oblong lanceolate, 
4 to $ of an inch long, laciniately lobed, lobes small, 
margins inflexed, forming cucullate scariose universal 
indusia. Veins forked, obscure; venules free. Sporangia 
sub-terminal. Sort punctiform, contiguous, included under 
the cucullate indusia, ultimately confluent, 
Type. Cheilanthes speciosissima, A. Braun. 
Illust. Fée Gen. Fil, t. 13, fig. 1; Moore Ind. Fil, 
p. 28, A. 
 Oss.—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- 
chlena and Cheilanthes, 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- 
smform margin, 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, Moore (P. mexicana, Fée ; Cheilanthes —— 
speciosissima, Kze. Analct., t. 23). 
