FIELD COLUMBIAN MUSEUM BOTANY, VOL. III. 



sagittate-ciliate; sporangia many, slightly veined; spores ovoid to 

 phaseoloid, opaque, and reticulately invested with the remains of the 



transparent, placentoid mem- 

 brane. 



The plant is called ZIZTAL- 

 CHEN, "Refrigerant," by the 

 Mayas, who use several species 

 of ferns as cooling applications 

 in fever conditions. 



Hab. Shady places, in 

 sand, under the edges of rocks, 

 and in crevices of the walls of 

 cenot^s: Merida, at the 

 Quinta del Obispo, Schott n ; 

 Cedral, Cozumel, Jan. 5, 1895, 

 Mills paugh Armour Exped.,35, 

 j6; at the cenot6 of Xcholac, 

 Gaunter 543; and near San 

 Miguel, Cozumel, Millspaugh 

 PL Utowana 1485. In the Cozumel specimens the fronds are taller 

 than is usual, the upper portion being more elongated than in 

 the type, and deeply pinnatifid to the acuminate apex, with the lobes 

 more or less deeply cut, but not laciniated. Quite unlike in appear- 

 ance the smaller, normally deltoid, forms of the mainland, with 

 entire, or nearly entire upper third, but otherwise the characters are the 

 same. The species, however, like all other Asplenieae, is an extremely 

 varied one, and the Cozumel forms are no greatly marked exceptions. 



Asplenium dentatum Linn. Sp. PL 1540. 



A. pygmceum Linn, in part. 



Fronds linear-oblong, pinnatisect; segments mostly opposite, 

 8-i2-jugal, sub-distant especially below, cuneate-elliptical, blunt, 

 more or less sharply serrate-den- 

 tate above; veins simple, or the 

 lowest pair forked at the apex. 

 Stipes lax, green-margined 

 especially above. Sori oblong, 

 scaphoid, 3-5 on each segment, 

 arranged on the inner margin of 

 each of the oblique veins, the 

 free margin erose - denticulate; 

 sporangia many, heavily anasto- 

 mose-ridged; spores phaseoloid, 

 anastomosely ridged and winged 

 by the remains of the hyaline 

 placentoid membrane. 



Fertile fronds 14-20 cm long, 

 sterile about 6 cm. Our specimens 

 appear depauperate when com- 

 pared with the large plants of this species from Jamaica, and the Isle 

 of Pines. 



Hab. At the Cenot de Telchaguillo, Schott 747. 



