PLATE XLV 



PACK 



Figs. 1, 2. BATOSTOMELLA INTERPOROSA n. sp 270 



1. Vertical section, X 20, through the center of a branch. 



2. Tangential section, X 20, showing the numerous acanthopores and 



mesopores. 



Helderberg formation, Keyser member, Devil's Backbone, 

 Maryland. 



Figs. 3-6. DIPLOSTENOPORA SILURIANA (Weller) 277 



3. Tangential section, X 20, cutting both mature and immature 



region. 



4. Portion of mature region of the same section, X 35. 



5. Vertical section, X 20, with a second layer of zooecia on the left. 



6. One-half of the same, X 35, illustrating the wall structure and 



perforated diaphragms in more detail. 

 Helderberg formation, Keyser member, Devil's Backbone. 



Fig. 7. SEMICOSCINITJM PLANUM n. sp 285 



Transverse section of the type specimen, X 12, introduced to show the 

 expanded carina. Helderberg formation, Keyser member, 

 Hyndman, Penna. 



FigS. 8-11. FlSTULIPOREIXA MARYLANDICA n. Sp 266 



8. Portion of a rather narrow zoarium, natural size. 



9. Tangential section, X 20, passing through a macula and adjoining 



zooecia. 



10. Several zorecia of the same section, X 35, exhibiting granular 



structure of lunarium. 



11. Vertical section, X 20, showing a portion of a solid branch. 



Helderberg formation, Keyser member, Cash Valley. 



Figs. 12-14. ORTHOPORA RHOMBIFERA Hall 286 



12. Tangential section, X 20, illustrating quincuncial arrangement 



and rhomboidal shape of zooscia in an average example. 



13. Tangential section of an old zoarium, X 30. 



14. Vertical section, X 20. 



Helderberg formation, Keyser member, Devil's Backbone. 



Fig. 15. FENESTELLA (CYCLOPORINA) ALTIDORSATA n. sp 282 



Transverse section, X 12, showing the carinated obverse and reverse 

 sides and the ovicell-like structure on the sides of the carina. 

 Helderberg formation, Keyser member, Devil's Backbone. 



36 



