I9I4.] SOUTHEASTERN NORTH AMERICA. 145 



fern type liable to be present in coastal thickets is the genus Lygo- 

 diiim with its scandent habit, and this genus is represented in the 

 Wilcox flora by both sterile and fertile fronds. It is likewise com- 

 mon in the Claiborne and Vicksburg floras and in Tertiary floras 

 generally. Besides Lygodimn, the family Schizaeaceae is represented 

 by a species of Aneiinia which must also be considered to have been 

 a coastal type in the early Eocene as are some of its species at the 

 present time, since very similar species of Aneiinia are found at a 

 very large number of Eocene coastal deposits both in this country 

 and abroad. 



The remaining four species of Wilcox ferns are all referable to 

 the family Polypodiacese which is the dominant existing family of 

 the fern phylum. The two species of Asplenium are types readily 

 matched by existing Central American species. The Ptcris, not cer- 

 tainly identified as a true species of this common cosmopolitan type, 

 had stout coriaceous fronds and may have been transported since it 

 occurs at only two localities in the Wilcox and at one of them it 

 is in a fragmentary condition. This supposition receives some sup- 

 port from its presence in the basal Eocene of the Rocky Mountain 

 province after the sea had withdrawn from that area and after there 

 had been a large amount of volcanic activity and more or less uplift. 

 The genus Meniphylloides is a unique type as yet peculiar to the Wil- 

 cox flora although it is closely related to the similarly unique genus 

 Meniphyllum Ettingshausen and Gardner from the Middle Eocene 

 (Lutetian) of England and both are closely related to and possibly 

 tlie progenitors of the existing genus Meniscitim which has at least 

 one species that is close to the Wilcox form, Meniphylloides is 

 only found at two localities near the top of the Wilcox and its prob- 

 able habitat is not known. The remains are broken but are asso- 

 ciated with a typical strand flora. 



It will be seen that of the Wilcox ferns whose habitats can be 

 surmised all are coastal types and when we recall that the mainland 

 was relatively low throughout Wilcox time it is not surprising that 

 the ferns are not more strongly represented. By a specialization of 

 habitat in modern equatorial regions a considerable proportion of 

 the flora becomes epiphytic, the smaller ferns being commonly so. 

 None of the members of the extensive Wilcox flora can be regarded 



PROC. AMER. PHIL. SOC, UII. 2I4 J, PRINTED JULY 10, I9I4. 



