﻿ulrich-bassler] revision of paleozoic bryozoa 



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Pierce limestone, Stones River formation, Murfreesboro, 



Tennessee. 



Orbignyella lamellosa I Ulrich) V- 



Tangential section of a single zooecium, X 35. (Introduced for 

 comparison.) 

 Richmond formation, Wilmington, 111. 



Prasopora patera new species V- - [) 



Tangential section, X 20, exhibiting the angular form and thin 



walls of the zooecia and the comparatively few mesopores. 

 Vertical section, X 20, showing normal character, seen in such a 



section. . ... 



Vertical section, X 20, showing the superficial extremities ol two 

 zooecial tubes and a case where the mesopores winch occur 

 further down in the section appear to have been crowded out. 



Vertical section, X 20, showing a mesopore succeeded by a rap- 



. idlv developing zooecium. 



Hermitage beds of the Trenton, 4 miles north of Columbia, 



Tennessee. 



Plate VII 



Homotrypella nodosa new species P- - >I 



Fig i. Vertical section, X 20. . . 



' ' 2,3. Tangential sections. X 20 and X 35, showing the thick, inflected 

 walls and numerous acanthopores. 



Leipers division of the Lorraine, Columbia, I ennessee. 



Mesotrypa echinata new species 1' - -'-' 



Tangential sections, X 20 and X 35, exhibiting the small angular 

 zooecia and large acanthopores. 

 6 Vertical section, X 20, passing through two mature regions with 

 an immature zone between and showing the crowded dia- 

 phragms, which are characteristic of this species. 



Lower part of the Catheys limestone of the Trenton, Nash- 



ville, Tennessee. 



Mesotrypa angularis new species P- 3 



7 Tangential section. X 20. The large cells on the right belong 

 to a macula, while those on the left are of ordinary zooecia. 

 The figure shows an average in the development of acantho- 

 pores, mesopores, and thickness of zooecial walls. 



8 V tangential section of an ordinary zooecium, X 35. 

 Q A vertical section, X 20. with the mesopores limited to the imma- 



' cure (lower) region and the acanthopores strongest ,11 the 



mature region. 



Lexington limestone of the Trenton, Frankfort, Kentucky 



Dekayella foliacea new species P- -'• 



10 Tangential section. X 20, showing aged condition in which the 

 Jails are thickened, the mesopores reduced to a minimum, and 

 the smaller set of acanthopores nearly obsolete. 

 „. Tangential section, X 35. exhibiting the normal development ot 



the two sets of acanthopores. 

 12 Vertical section, X 20. 



Lexington limestone of the Trenton. Lexington. Kentucky. 



4.5- 



