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ANNUAL REPORT SMITHSONIAN INSTITUTION. 1918. 



the features of which are probably overestimated in discussing their 

 interrelationships. The name, derived from the Greek root for 

 common or general, is adopted in allusion to their synthetic char- 

 acters, and the group is considered to have been much wider than 

 is indicated by our knowledge of the two families Botryopteraceae 

 and Zygopteraceae, and in the accompanying phylogenetic diagram 

 is used as the starting point of the fern phylum. 



Without attempting to formulate the theoretic characters of the 

 Eofilices or setting diagnostic bounds to the Coenopteridae as here 



Fig. 2. — Diagram showing the geologic history and interrelationships of the ferns. 



used, we may pass to a brief consideration of the two known, 

 families. 



The Botryopteraceae at present embrace three genera: Gram- 

 matopteris and Tubicaulis based upon Permian stem anatomy, and 

 Botryopteris based upon stem and sporangial structural remains 

 ranging in age from the Lower Carboniferous to the Permian. 

 Little is known of the habits of fronds of these types and they have 

 not been definitely correlated with material preserved as impres- 

 sions. They had slender monostelic stems exarch in Grammato- 



