166 



Plate VII. 



Page. 



Hntostoitia rtiriahHc I'lricli IHO 



1. Shallow Tiingcntial section, showiiij; thin walls. Weishurg, 



Ind.' 

 la. Deep tangenital section, showing thick walls. Weishurg, Ind. 

 lb. Tangential section, showing numerous indi.stinct acantho- 



pores. Ballstown, Ind. 

 Ic. Longitudinal section. Weishurg. 

 liato.stotna prosfieri nov IHl 



2. Typical tangential section, showing large acanthopores and 



numerous mesoj tores. Weishurg, Ind. Upper Waynesville. 



2a. Tangential section, showing (■oiiiniuiiication jMires. Weis- 

 hurg, Ind. I'pper Waynesville 



2b. Tangential section, showing unusually large and numerous 

 acanthoiK>res. Weishurg. Iiid. riijier Wiiynesville. 



2c. Ixjngitudinal section. 

 liatostoma rariaiiK (James i 14S 



3. Typical tangential section. 



3a. Longitudinal section, showing spiny acanthopores crossed 

 by diai)hragnis. 



' All figures magnifiod 44 diamolrrs. 



