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 insl. by Fournier (Bull.Soc.Fr.il): 253), 

 who only with doubt referred them to D. tetragona. I am inclined to consider var. 

 2, 5 and 6 distinct species, and var. I a variety of D. tetragona. 



var. 1. Resembles in size and colour the common tetragona, but the basal 

 veins connivent to sinus; 12 — 14 veins; sori subcostular; sporangia glabrous. 

 Guatemala: San Felipe, Depart. Retalhuleu, 2050', Donnell Smith nr. 2733 (W). 



var. 3. Size of Ü. tetragona, colour intense, green, opaque not shining; lower 

 veins occasionally anastomosing but more often the 2 — 3 lower ones are connivent 

 to sinus. Sori small, dark, almost medial; sporangia glabrous. 



This is Polyp, tetragonum Liebm. Mex. Bregn. 211, and it is probable that Lieb- 

 MANN was right in considering it specifically distinct from D. tetragona = P. imbri- 

 catum Liebm. 

 Mexico: Vera Cruz, Buenaventura, H. Ro.ss nr. 1073 iCC| La Junta, H. Ross nr. 1113 (CC), Rovi- 



ROSA (Wl, LlEBMANN (H). 



Similar forms are 



Guatemala: San Felipe, Dep. Retalhuleu, coffee-plantation, Maxon and Hay nr. 3513 (W); Hhizome 

 long horizontally creeping; sori costular. 



Honduras: San Pedro Sula, C. Thieme ed. J. D.S. nr. 5694 (Cl; Pinnæ narrower and very remote; spo- 

 rangia setose. 



var. 3. Very like var. 2, but segments falcate and veins about 15; lower pinnæ 



with a cuneate entire base and all long acuminate. Sporangia setose; rhizome erect. 



Perhaps a variety of D. nicaraguensis. 



Guatemala: Cubilquitz, 350 m, v. Tuerckheim ed. J. D. S. nr.^8(U6 (C, W) — Volcan Tecuaniburro, 

 Hkvde et Lux ed J. D. S. nr. 4685 ß, C, W) — San Felipe, Donnell Smith nr. 2733 (W) — 

 near the Finca Sepaeuite, Cook and Griggs nr. 372 (W). 



var. 4. Intermediate between D. tetragona and D. obliterata. Pinnæ incised Vs, 



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. tetragona and D. nicaraguensis. They resemble the former in size, the 

 setose sporangia, and the truncate or slightly narrowed base of the pinnæ, and the 

 latter in venation, the light colour and the semiterete costa of the pinnæ beneath. 

 As a rule the pinnæ are incised '/.t- '/a with 6 — 8 veins connivent to sinus. Sori 

 inframedial, small, yellowish. Texture firmer than D. tetragona, thinner than D. 

 nicaraguensis. 



Costa Rica: Puerto Viejo, Pittier nr. 7489 (B, W), 6937 (C, W) — Guacimo, Llanos de Sta. Clara, 

 ToNDUz nr. 14578 (W — forets de Bornea, Pittier nr. 4824 (W) Snerre, Llanuras de 

 Sta. Clara, Donnell Smith nr. 6897 (W) — forets de Tuis, Tonduz nr. 11312 (C) — Jimenez, 

 Alfaro nr. 16479 (C). 



Panama: Bocas del Tore, J. Hart nr. 55 (W). 



