I 



EXPLANATION OF PLATE 4 



Figs. 1-3 Neo::aphrentis tenclla (Miller); plesiotypes ; X 5 p. 45 



1, Transverse section, early ephebic stage ; long thickened counter septum lying to one side 

 of counter-cardinal plane, very short cardinal septum, and pinnate arrangement of septa 

 in cardinal quadrants are characteristic ; after Grove. 



2, Transverse section, middle neanic stage ; septa radially arranged, nearly reach center, 

 and their fused axial edges form stereotheca ; after Grove. 



3, Transverse section, late ephebic stage ; quadripartite septal grouping notew^orthy ; 

 after Grove. 



Figs. 4-7 HapsiphyUmn (Homalophyllites) calceolus (White and Whitfield); plesiotypes . p. 43 



4, Transverse section, late ephebic stage ; X 5 ; very short cardinal septum in pronounced 

 f ossula, very thick epitheca and sparse tabulae are characteristic ; circular cross- 

 section is unusual ; University of Cincinnati 24311. 



5, Transverse section, late neanic stage ; X 10 ; long bifid cardinal septum, sparse tabulae, 

 and poorly defined stereotheca are noteworthy ; epitheca eroded away. 



6, Transverse section, early neanic stage ; X 10 ; fused cardinal and counter septa is im- 

 portant feature ; epitheca eroded away ; figs. 5 and 6 are from same specimen. 



7, Longitudinal section ; X 5 ; thick epitheca with constrictions well shown on right side 

 and arched tabulae are noteworthy ; dark central areas are stereotheca ; outlined white 

 areas are possibly morphologic structures, possibly incidental replacement. 



Figs. 8-11 Psciidocryptophyllum camim Easton, n. sp. ; holotype ; X 5 p. 34 



8, Longitudinal section ; tabulae recurved at periphery, steeply arched, depressed and 

 thickened axially. 



9, Transverse section, early ephebic stage ; cardinal septum thick, counter septum thin ; 

 no secondary septa present. 



10, Transverse section, late neanic stage ; cardinal septum thinner than counter septum ; 

 secondary septa retreating from axis ; dark axial area is where plane of section cut 

 tabula. 



11, Transverse section, late ephebic stage ; meta-septa added in counter quadrants ; epitheca 

 irregular at positions of interseptal ridges and septal grooves ; note swollen tips of 

 counter-laterals. 



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