50 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
cm. long, stramineous, subquadrangular, sulcate, bearing a few large flaccid yellowish 
brown scales near the base, elsewhere nearly glabrous, or with a few linear or fibrillose 
tortuous scales above, these extending along the rachis but readily deciduous; lamina 
narrowly ovate, deeply bipinnatifid nearly throughout, 29 to 36 cm. long, 10 to 17 cm. 
broad, comprising 15 to 17 pairs of spreading mostly falcate pinnze; middle and lower 
pinne 6 to 8.5 em, long, 1.5 to 2em. broad at the middle, subpinnate, strongly ineequi- 
lateral at the base, the superior basal segment much the largest, free, rhombic-ovate 
from an unequal narrowly cuneate base, the inferior one minute, free, the next 5 to 
8 pairs narrowly to broadly rhombic-ovate, 8 to 12 mm. long, very oblique (the distal 
margin lying close to the narrowly alate secondary rachis), the apical segments much 
narrower, fully adnate and strongly decurrent, finally evident only as deep serra- 
tions at the acuminate apex; all the segments sharply acuminate but scarcely spines- 
cent; apical pinne 1 to 2 cm. long, inserted 1 to 1.5 cm. apart; leaf tissue membrano- 
chartaceous, the under surfaces very sparingly and minutely fibrillose-paleaceous, 
mainly along the veins; rachis stout, very narrowly alate in the upper part, terminat- 
ing in a large viviparous bud 1 to 2 cm. above the apical pinnae; venation concealed, 
mostly flabellate, repeatedly dichotomous, the segments without definite midribs; 
sori large, irregularly biserial, the larger segments with 2 to 5 pairs. 
Type in the U. S. National Herbarium, nos, 520201 and 520202, collected upon 
rocky slopes bordering humid forests in the immediate vicinity of Holly Mount, 
Mount Diabolo, Jamaica, altitude about 750 meters, May 25 to 27, 1904, by William 
R. Maxon (no. 2283). 
The relationship of the present species is clearly with P. dissimulans. From this 
it differs mainly in the paler scales of the rhizome, in its different leaf shape, fewer 
pinne and minute inferior basal pinnules, in its flagelliform (and not foliose) apex, 
and in its sharply acuminate, rather than rigidly spinescent, segments, - P. dissim- 
ulans is the most rigidly coriaceous of all the West Indian allies of P. triangulum 
while P. ambiqguum has singularly flaccid fronds for a member of thisgroup. P. hetero- 
lepis, though superficially resembling P. ambiguum to a certain extent, differs in 
nearly all essential details. 
EXPLANATION OF PLATE 27, A middle section of the type specimen. 
Polystichum plaschnickianum (Kunze) Moore. 
This species, known hitherto only from Jamaica, has been collected recently in 
Santo Domingo by von Tiirckheim (no. 3038). The specimens, which are typical, 
are from the vicinity of Constanza, altitude 1,350 meters. 
Polystichum polystichiforme (I*ée) Maxon. 
Known previously only from Cuba and Jamaica. Collected recently in Porto Rico 
by Brother Hioram, his specimens (no. 245) from Mount Torresilla, July, 1911. 
Polystichum triangulum (L.) Fée. 
This species, mentioned in the last paper as inhabiting only Santo Domingo, Cuba, 
and Jamaica, occurs also in Guatemala. The record rests upon plants collected by 
von Tiirckheim near Coban, Alta Verapaz, altitude about 1,350 meters, on rocks, and 
distributed by Captain Smith as no. 851. 
Specimens from the vicinity of Constanza, Santo Domingo, altitude 1,190 meters, 
February, 1910, von Tiirckheim 2933, distributed as Polystichum triangulum vay. iliei- 
folium Fée are not Polystichum ilicifolium Fée. They are, rather, referable to P. 
trianqulum, but represent an unusually spiny form ef the species. 
Polystichum wrightii (Baker) C. Chr. in herb. 
Polypodium wrightit Baker in Hook. & Baker, Syn. Fil. 304. 1867. 
Dryopteris sauvallei C. Chr. Ind. Fil, 291, 1905. 
Polystichum longipes Maxon, Contr. Nat. Herb. 18: 34. pl. 6. 1909. 
The above synonymy relates wholly to a Cuban species known only upon Wright's 
no. 3924. Baker, strangely enough, first described the species under his section 
