AN ENUMERATION OP CULTIVATED FERNS. 239 



bi-tripinnate, 5-15 feet long. Veins pinnate; venules free, 

 simple. Receptacles punctiform, terminal. Sori globose, large, 

 reflexed. Indusium bivalved, coriaceous ; tlie outer valve (acces- 

 sory indusium) concave, cucullate, conniving with the smaller, 

 usually less cucullate, inner valve or special indusium, forming 

 an unequal valved cyst. 



1. D. arborescens, L'Herit. ; Hook. Sp. Fil t. 22 A. D. 



auricoma, Spreng. Balantium auricomum, Kaulf. ; 

 Presl. Dicksonia integra, Sw. Balantium arborescens, 

 Hook. Gen. Fil t. 30. St. Helena. 



2. D. antarctica, Labill. Nov. Soil. t. 249. Balantium 



antarcticum, Presl. Cibotium Billardieri, Kaulf. 

 Australia. 



3. D. Sellowiana, Hook. Sp. Fil 1, t. 22 B. Balantium 



Sellowiana, Presl. Tropical America. 



4. D. squarrosa, 8w. ; Sdik. Fil. 1. 130. New Zealand. 



5. D.lanata, Colenso ; Hook. Sp. Fil. t. 23 C New Zealand. 



128. CIBOTIUM, Kaulf. 



Vernation fasciculate, decumbent, or erect and arborescent, 

 densely criniferous. Fronds tripinnatifid, 5-15 feet long, gene- 

 rally glaucous beneath. Veins forked or pinnate ; venules free. 



Genus 128. Portions of barren and fertile fronds, natural size. 



Receptacles punctiform, terminal. Sori dentiform, reflexed. 

 Indusium bivalved, horny, the outer valve (accessory indusium) 

 concave, cucullate, adnate to the margin ; the inner (special 

 indusium) smaller, and conniving with the outer, forming an 

 unequal bivalved cyst. 



