2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



acuminate from a deltoid-ovate rounded base (here 0.7 to 1.1 mm. 

 broad), light brown in mass, definitely but not sharply bicolorous, 

 the darker median area composed of short to elongate, distinctly 

 luminate cells with reddish brown sclerotic partition walls ; marginal 

 zone composed of mostly transverse, thin-walled, whitish cells in 2 

 to 4 rows, the outermost ones disposed as a deeply and irregularly 

 denticulate margin, the teeth cleft. Fronds several, approximate, 

 4 to 8 cm. long; stipe 1.5 to 3 cm. long, light brownish, narrowly 

 marginate along- the ventral face ; lamina deltoid-oblong, long- 

 acuminate, 2.5 to 5.5 cm. long, 1 to 2.5 cm. broad, obliquely pinnatifid 

 to within 1.5 mm. of the rachis, the rachis evident beneath, dark 

 brown ; segments 5 to 9 pairs, oblong to linear-oblong, dilatate, 

 unequal, the upper ones gradually shorter, finally evident as short 

 oblique lobes merging into the narrowly elongate apex ; margins 

 subentire to lightly crenate ; midveins concealed ; veins 4 to 6 

 pairs in the larger segments, wide-spreading, mostly once forked 

 half way to the margin, the sori terminal upon the first branch, the 

 other branch ending in a minute depressed hydathode near the mar- 

 gin ; lower surface sparsely paleaceous, the scales resembling those 

 of the rhizome in general structure, but much shorter (0.3 to 0.5 mm. 

 long) and commonly elongate-deltoid, the dark cells with larger 

 lumina, the margins more deeply lacerate-denticulate ; sori 3 to 

 6 pairs, medial, not concealed by scales ; sporangia glabrous, the 

 annulus 14-celled; spores diplanate, pale, granulose. Leaf tissue 

 elastico-coriaceous, the segments tortuous or irregularly involute 

 in drying, or the whole lamina reversely circinnate. 



Type in the U. S. National Herbarium, no. 700538, collected in low 

 hills back from the coast near Mollendo, Peru, August 5, 1901, by 

 R. S. Williams (no. 2978). Collected also at the same locality, 

 August 25-26, 19 14, by Dr. and Mrs. J. N. Rose (no. 18989). 



Related closely to P. pycnocarpum and several allied South Ameri- 

 can species variously confused under this name. These are treated 

 at length in a paper soon to be published in the Contributions from 

 the U. S. National Herbarium. 



POLYPODIUM PYCNOCARPUM C. Chr. 

 Peru : Near Oroya, alt. 3,700 meters (19467). 



ADIANTUM EXCISUM Kunze 

 Chile: Vicinity of Choapa, alt. 235 meters (19511). 



