222 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



STUDY OF THE LIFE PROCESSES IN FOSSILS 

 BY E, S. BASSLER 



The last paper of the session was a short discussion of the methods of 

 recognizing the life processes in fossils, and of the importance of taking 

 these factors into account in the discrimination of species. The remarks 

 were based mainly upon the cyclostomatous bryozoa, where species ex- 

 actly alike externally show by their ovicells, or organs of reproduction, 

 that they belong far apart. 



The following papers were read by title : 



SPONGES OF THE MIDDLE CAMBRIAN 

 BY CHARLES D. WALCOTT 



INORGANIC EVIDENCES OF DISCONFORMITIES IN LIMESTONE 

 BY RICHARD M. FIELD 



At 5.30 the Society adjourned. 



Minutes of Sectional Meeting of Vertebrate Paleontology 



The section convened at 3.30 p. m. Tuesday, December 30, at the con- 

 clusion of President Jackson's address, with Walter Granger as chairman 

 and Messrs. Matthew, Gregory, Camp, Lull, Loomis, Troxell, Thorpe, 

 C'haney, Sinclair, Stock, and Buwalda present. 



The following papers were then presented, the first one, on paleo- 

 botan}^, being included in this section on account of relationship to tlie 

 vertebrate faunas of the same region: 



FURTHER DISCUSSION OF THE ECOLOGICAL COMPOSITION OF THE EAGLE 



CREEK FLORA 



■ BY RALPH W. CHANEY 



(Al)stract) 



The Eagle Creek flora of the Columbia Gorge region is made up largely of 

 dicotyledonous arboreal forms, and the flora as a whole bears a strong resem- 

 blance to that now occupying the northeastern United States. Its most notable 

 feature Is a mixture of mesophytic and xerophytic types, the former dominat- 

 ing in number of species, the latter in number of individual leaves. Thi.s 

 mixture is interpreted as being due to a varied topography during the Eagle 

 Creek epoch — an interpretation which suggests a bajada mode of origin for the 

 Eagle Creek formation. 



