10 F I L I C E S. 



Hab. San Francisco, California. 



The founders of this species considered it distinct from P. vulgare 

 of Linnaeus, on account of its oval sori and pellucid fronds, with the 

 segments becoming smaller at the base; the first two of these cha- 

 racters being the only ones which apparently present any claims to 

 constancy, induces us to retain the species; we think, however, that 

 the P. Scouleri of Hooker and Greville's Icones Filicum, is not speci- 

 fically distinct from the present one, as in the work referred to, it is 

 represented as having a forked free venation; in which particular, as 

 well as in the circumscription of the fronds, it accords with forms in 

 our possession, of what we are perfectly satisfied belong to the true 

 P. intermedium of the authors of the Botany of Beechey's Voyage. 



In Hooker's Flora Boreali Americana, we find the P. Scouleri 

 referred to P. (Marginari) Californicum of Kaulfuss, which latter has 

 the lower exterior venules free and fertile, the upper ones angularly 

 anastomosing; while Presl more properly places it in his Ctenopteris 

 division of Polypodium, in which the venules are all free. 



13. POLYPODIUM PELLUCIDUM, Kaulf. 



Polypodium pellucidum, Kaulf. Enum. Fil. p. 101 ; Gaud. Bot. Freyc. Voy. p. 356; 

 Hook. & Arn. Bot. Beech. Voy. p. 103. 



Var. 8. Laciniis linear i-lanceolatis, acuminatis. 



Var. y. Laciniis lobato-dentatis ; lobis fertilibus. 



Hab. Sandwich Islands : on trees, and in open plains on decom- 

 posed lava, frequent ; on Mauna Loa, at an altitude of 8000 feet. 



Though closely allied to P. vulgare, yet the fronds are usually 

 larger, more coriaceous and rigid, with obtuse repand-dentate seg- 

 ments, and sori seated closer to the margin ; veins pellucid, with a 

 faint nervule perceptibly leading from the sori, and terminating in 

 the sinus of the teeth, being an apparent continuation of the fertile 

 veinlet. Plant altogether very variable in the form and indentations 



