131 183 



D. augescens is a very critical species, very well described and figured by 

 Kunze. It is almost exactly intermediate between D. normalis and D. serra, agreeing 

 with both in the creeping rhizome and the shape and colour of the scales. In 

 general habit it resembles Ü. normalis, from which it differs by 1) the firmer la- 

 mina, which rather suddenly narrows upwards into a pinnatifid apex but nol having 

 a distinct terminal pinna as D. serra, 2) the narrower pinnæ, about 1 cm broad, 

 the lower ones a little narrowed towards the shortly auricled base, 3) the presence 

 of small, hairy scales on the costæ beneath, exactly resembling those of D. serra, 

 similar scales are often found on the rachis, 4) the very acute, oblique or patent 

 but not falcate, oblong-triangular segments with somewhat revolute edges, and 

 5) by the veins being prominent beneath. — From D. serra, which it resembles 

 very much in pubescence by hairs and scales, it differs by li the shorter pinnæ, 

 which are rarely more than 12 cm long, less acuminate and more dee])ly cut, 

 2) the want of a distinct terminal pinna, 3) the lower basal segment of most pinnæ 

 not adnate to rachis, 4) thinner texture and less prominent costæ, 5) the non-falcate 

 segments, and 6) the basal anterior vein only running to sinus, the posterior one 

 generally reaching the margin a little above the sinus. 



— Stipes slightly scaly downwards, rather slender, 30-50 cm long; lamina ot 

 the same length, fresh- or darkgreen; costæ above more or less pubescent, the 

 upperside elsewhere glabrous; underside not glandulose. Veins about 8 to a side; 

 sori a little supramedial, furnished with persistent, setose indusium. 



The following specimens are typical: 



Cuba: Prov. Habana, Nazarene, Baker nr. 1893 (W) ; Puiites Grandes, H. Leon nr. lüö (W); near San- 

 tiago de las Vegas, Wilson nr. 444 |W) — San Antonio de los Banos, Baker & O'Donovan 

 nr. 4132 (.W) — Tabureto, E. Otto nr. 215 (B) — Prov. Pinar del Rio, Guanajay, Earle et 

 Wilson nr. 1511 (W); near Caiamito, Palmer et Riley nr. 705 (W) — Isle of Pines, Palmer 

 et Riley nr. 1120 (W). 



Mexico; San Luis Potosi, near Rascon, Edw. Palmer nr. 6G1 (W); near Taneanhuitz, C. et E. Seler 

 nr. 695 (B); Schaffner sine num. (B) — Jalisco, near Guadalajara, Ed\v. Palmer nr. 76 (W) 

 — Colima, San Marcos, M E. Jones nr. 529 (W) — Tamaulipas, near Victoria, Edw. Palmer 

 nr. 569 (W). 



Costa Rica: Cartago, J. J. Cooper, ed. J. D. S. nr. 6050 (W). 



The following specimens from Bahama Islands resemble very much D. 

 serra in size and are perhaps belonging to that species; still they agree best with 

 D. augescens in most differential characters. 



Andros, Niçois, Town, J. and A. Northrop nr. 441 (B); Providence, Nassau, 

 J. and A. Northrop nr. 173 and 240 (B); Rawson W. Rawson (B); Eggers 

 nr. 4178 (H). 



While the Mexican specimens enumerated above are very typical some other 

 specimens are scarcely to distinguish from D. normalis var. Lindheimeri ; these spe- 

 cimens again are intermediate between the type and the larger, common Mexican 

 fern registered in my Index as D. Feei C. Chr. It is impossible to me to distin- 



24* 



