rLOK^V OF XOETil-WESTERN MEXICO. 341 
670. Cheilanthes cnneata, Link, 1. c. p. 03.— Kunze in Schk. Fil. pp. 73, fi, 36.— Hook. 1. c. 
p. 107. excl. syn. Mart, et Gal. Sierra Madre (n. 1932) ; Cerro de Pinal (n. 1450). 
671. ALLOsoars margmat-m, J. ^m.—Cheilanthes nmryhmUt, II.B.K., Nov. Gcu. ct Spec. Am. 
vol. -vii. t. 669.— Link, Fil. Hort. Bcrol. p. 02.— II.,ok. Sp. Fil. vol. ii. p. \m.—ChtUanihcs duBi'o- 
phylla, Mart, et Gal., Fil. Mex. p. 47. t. W .—Allosorvs ciUatus, Prcsl, Rcliq. H^nk. vol. i. p. 59. 
Near Guajimalpa, Toluca (Scliaffucr !) . Andes of Jlexico and Pcni generally. 
The habit and general character of thia and the following species agree so well witli tlie typical species 
of the genus Allosorus {A. crispus), that I have no hesitation in placing; them in Ihat genua. A. crispwi 
has an extensive geographical range in the temperate regions of the northern huuuBphere ; for, according to 
my view, the North American A. acrosticUidcs and the Himakyan A. Bmnoniana are oidy forms of the 
A. crispus of Europe, produced hy climatal influences, and it is probable that the examination of specimens 
froin the latitudes intervening between the limit of A. acrostichoides and the southern limit of the IMexican 
species will sliow that the whole are merely modifications of one species. 
072. Allosorus angustifolius , Presl, Pterid. p. \b2.~Chcihmthes angnsfifoUa, II.B.K. Gen. et 
Spec. Am. vol. i. p. 17. —Onychmm angmHfolium, Kunze in Schk. Fil. p. W.— Allosorus der.ompo- 
situs, jMart. et Gal., I.e. p. 48. t. 10. f. 2. Sierra Madre (n. 1927). 
673. Plecosokxjs Mexicanus, Fee, Gen. Fil. p. 151. t. 13. f. I.— Cheilanthes specwsissima, Kunze, 
Analect. Pterid. p. 35. t. 23.— Linn. vol. xiii. p. 145.— Hook. Sp. Fil. vol. ii. p. 103. Near Cliapul- 
tcpic (Schaffner!) ; Real del Monte (Hartwcg). 
The large size and squan^osc character of this Fern gives it the appearance of being more closely 
related to PoljUlclmm (P. aculeatum) than to the genus Cheilanthes, from which it differs in the sporangia 
being produced longitudinally on the venules, which, with the involute indusfeform margin, induced me to 
note on my first specimen that it was analagous to Jamesonia, but as it differs in habit from that genus as 
much as it does from Cheilanthes, I therefore deem it best to follow M. Foe in considcniig it the type of a 
distinct genus. 
674. Pelljsa sagittata, Link, En. Fil. Hort, Berol. p. 60.— Fee^ Gen. Fil. p. \2^.— Allosorus 
sagimtus, Presl, Kunze in Schk. Fil. Suppl. t. ^d.—Platyloma sagittata, J. Sm. Gen. Fil. I.e.— 
Allosorus cordatns, Presl, Hook, in Bot. Mag. t. 4098. — Platyhma cordata, J. Sm. 1. c. — Pteris sa- 
gittata et cordata, Cav., Willd. 1. c. p. 292. On rocks near Bclen, Cliapultepic, and Tacubaga 
(Schaffner !) 
For a long time I considered P. sagittata and P. cordata to be two distinct species ; but the examination 
of a greater number of specimens has now convinced me that the different appearances are only modifica- 
tions of one species. 
675. Pell^a flexvosa, Link, 1. c. p. 60. — Fee, Gen. Fil. p. 129. — AUosonis flewuosus, Presl, 
Kunze in Schk. Fil. Suppl. t. 23.— Hook. Ic. PI. Rar. t. 119. Sierra Jladre (n. 1910). On rocks 
about Tacubaga, Belen, and Chapultepic (Schaffner !). 
The scandent character of the frond and the refracted pinna; readily distinguish this from the preceding 
species. 
Q7Q. Pell^a ternifolia, Link, 1. c. p. 59.— Fee, Gen. Fil. p. \%^.— Pteris temifolia, Cav., Hook. 
et Grcv. Ic. Fil. t. 120.— P/m5 suhverticillata, Sw., AVilld. I.e. p. S75.— Allosorus subverticillatus , 
Presl, Pterid. p. 153. Near San Angel, Belen, on rocks (Schaffner !). 
