166 CHARACTERS OF TRIBES AND GENERA. 



delicate, their imperfect indusium and broad compound 

 sorus shows them to be related to Platyloma. 



They are natives of Tropical America, extending from 

 Chili to Mexico. 



* Fronds smooth. 



C. tenera, Fee (Bot. Mag., t. 3055) (v v.) ; C. pulchella, 

 /. 8m. (v v.) (Mart, and Gal. Fil. Hex., t. 10, /. 1) ; C. 

 Fendleri, Kze. 



** Fronds farinose. 



C. nivea, Desv. (v v.) (Kze. Fil., t. 22, /. 1 ; Lowe's Ferns, 

 1, t. 19, C.) ; C. Hookeri, /. Sm. (Lowe's Ferns, t. 10, /. 1) 

 (v v.) ; C. dealbata, Kze. ; C. flavens, Desv. (v v.) (Gymno- 

 gramma, HooJc. Fil. Exot., t. 47). 



76. ALLOSORUS, Bernh. (1806). 

 Cryptogramma, R. Br., 1823 ; Hook. Sp. Fil. 



Vernation fasciculate, ceespitose, acaulose. Fronds of two 

 forms, 6 to 10 inches high, tri-quadripinnatifid. Fertile 

 segments contracted, oblong or linear, 1^ inch in length, 

 margins membranous, revolute, oppositely conniving, 

 forming a universal indusium. Veins forked, free. Recep- 

 tacles terminal, elongated, or punctiform, becoming laterally 

 confluent, forming a broad or narrow transverse sorus on 

 each side of the mid-rib, and both included under the 

 universal indusium forming a siliqua. 



Type. Pteris crispa, Linn. 



Illust. Hook, and Bauer, t. 115 B. ; Moore Ind. Fil., p. 

 53 B, and 54, A. ; J. Sm. Ferns, Brit, and For., fig. 

 89 ; Hook. Syn. Fil., t. 3, fig. 29. 



OBS. This genus is founded upon the well-known Euro, 

 pean Fern, Pteris crispus, of Linnaeus, and is represented 

 in Himalaya by A. Brunoniana, and in North West America 



