262 210 
this species varies in venation, still it is remarkable that the West-Indian common 
form always has the basal pair of veins anastomosing. These free-veined Central- 
American forms were mentioned before, f. inst. by FounNrER (Bull. Soc. Fr. 19: 253), 
who only with doubt referred them to D. tetragona. I am inclined to consider var. 
2, 5 and 6 distinct species, and var. 1 a variety of D. letragona. 
var. l. Resembles in size and colour the common /eiragona, but the basal 
veins connivent to sinus; 12—14 veins; sori subcostular; sporangia glabrous. 
Guatemala: San Felipe, Depart. Retalhuleu, 2050', DoxNELL SwirH nr. 2733 (W). 
var. 2. Size of D. tetragona, colour intense, green, opaque not shining; lower 
veins occasionally anastomosing but more often the 2—3 lower ones are connivent 
lo sinus. Sori small, dark, almost medial; sporangia glabrous. 
This is Polyp. tetragonum Liebm. Mex. Bregn. 211, and it is probable that LrEB- 
MANN was right in considering it specifically distinct from JD. tetragona = P. imbri- 
catum Liebm. 
Mexico: Vera Cruz, Buenaventura, H. Ross nr. 1073 (CC) — La Junta, H. Ross nr. 1113 (CC), Rovi- 
ROSA (W), LIEBMANN (H). 
Similar forms are 
Guatemala: San Felipe, Dep. Retalhuleu, coffee-plantation, Maxon and Hay nr. 3513 (W); Rhizome 
long horizontally creeping; sori costular. 
Honduras: San Pedro Sula, C. TuigwE ed. J. D. S. nr. 5694 (C); Pinnae narrower and very remote; spo- 
rangia setose. 
var. 9. Very like var. 2, but segments falcate and veins about 15; lower pinnze 
with a cuneate entire base and all long acuminate. Sporangia setose; rhizome erect. 
Perhaps a variety of D. nicaraguensis. 
Guatemala: Cubilquitz, 350 m, v. TuEnckHEIM ed. J. D. S. nr*8646 (C, W) — Volcan Tecuamburro, 
HEvpE et Lux ed J. D. S. nr. 4685 |B, C, W) — San Felipe, DoNNELL SwrirH nr. 2733 (W) — 
near the Finca Sepacuite, Cook and GnicGs nr. 372 (W). 
var. 4. Intermediate between D. tetragona and D. obliterata. Pinnze incised !/s, 
basal pair of veins anastomosing with a short meniscioid branch; above them 2—4 
pairs of veins connivent to sinus; sori medial: sporangia densely setose. 
Guatemala: Gualan, Depart. Zacapa, W. A. KELLERMANN nr. 4869 (W). 
var. 5. Here I place a number of rather different forms, which are intermediate 
between D. lelragona and D. nicaraguensis. They resemble the former in size, the 
setose sporangia, and the truncate or slightly narrowed base of the pinne, and the 
latter in venation, the light colour and the semiterete costa of the pinnz beneath. 
As a rule the pinnz are incised !/—!/» with 6—8 veins connivent to sinus. Sori 
inframedial, small, yellowish. Texture firmer than D. fetragona, thinner than D. 
nicaraguensis. 
Costa Rica: Puerto Viejo, Pirrier nr. 7489 (B, W), 6937 (C, W) — Guacimo, Llanos de Sta. Clara. 
ToNpuz nr. 14578 (W) — foréts de Bornea, PrrTIER nr. 4824 (W) — Suerre, Llanuras de 
Sta. Clara, DONNELL SwrrH nr. 6897 (W) — foréts de Tuis, Tonpuz nr. 11312 (C) — Jiménez, 
Auraro nr. 16479 (C). 
Panama: Bocas del Toro, J. Hart nr. 55 (W). 
