TREE FERNS OF NORTH AMERICA—MAXON. 491 
PLATE 12. 
Segment of Hemitelia horrida, showing the ample, hood-shaped, laterally attached 
indusia which protect the young sporangia. Specimen from the upper 
slopes of the Gran Piedra, eastern Cuba, altitude about 3,000 feet, April 
14, 1907, Mazon 4034. Eight times natural size. 
PuLate 13. 
Fie. A. Alsophila blechnoides, the only American tree fern having more than one 
sorus upon a veinlet. Specimen from hilly forest above Las Cascadas, 
Canal Zone, Panama, altitude about 500 feet, February 19, 1911, Mazon 
4887. 
B. Sori and indusia of Dicksonia navarrensis. Specimen from mountains 5 miles 
south of Cartago, Costa Rica, altitude 5,500 feet, May 12, 1906, Mazon 513. 
C. Sori and indusia of Culcita contifolia. Specimen from humid forested slopes 
near Cerro de la Horqueta, western Chiriqui, Panama, altitude 6,500 feet, 
March 18, 1911, Mazon 5459. 
D. Sori and indusia of Cibotium Schiedei. Specimen from Zacuapan, Vera 
Cruz, Mexico, November, 1908, Purpus 1976a. 
All at four times natural size. 
PuaTeE 14. 
Section of a pinne of Dicksonia navarrensis at natural size. Specimen from mountains 
5 miles south of Cartago, Costa Rica, altitude 6,500 feet, May 12, 1906, 
Maxon 513. 
Puate 15. 
oe of a pinna of Cibotiwm Schiedei at natural size. Specimen from Zacuapan, 
Vera Cruz, Mexico, November, 1908, Purpus 1976a. 
