PLATE V. 



PAGE. 



Figs. 1 to 10. PHYLLOPORINA CORTICOSA Ulr 212 



1. A frond of this species exposing the poriferous or obverse side; natural size. 



2 and 6. Eeverse side of a fragment, natural size and a portion :<9. 



3 and 7. Obverse side of another fragment, natural size and a portion *9. 



4 and 5. Two specimens of the basal portion of the zoarium, natural size. 



8. Tangential section, xis, cutting the zooscial tubes at varying depths from the surface. 



9. Transverse section of several branches, xis. 



10. Vertical section of a branch, xis. 



Upper third of the Trenton shales, near Cannon Falls, Minn. 



Figs 11 and 12. EHINIDICTYA GEANDIS, n. sp 136 



A fine example from the -'Lower Blue" limestone at Dixonlll., natural size and a portion 

 xg. (See also Plate VI.) 



Figs. 13 to 18. RHINIDICTYA MINIMA Ulr 132 



13. Three fragments of the natural size. 



14 and 15. One of them xg, and a portion of same X18, showing the small zooecial apertures 

 and grano-striat'e character of the interspaces. 



17. Tangential section of the variety MODESTA, xis, showing the appearences of the zooecia 



at various depths beneath the surface. 



18. Tangential section of the typical form of the species, xis. 

 Upper part of the Galena shales, near Cannon Falls, Minn. 



Figs. 19 to 21. EHINIDICTYA PAUPERA Ulr 129 



19. A nearly complete specimen, natural size. 

 20 and 21. A fragment, natural size xg and xis. 



Upper third of the Trenton shales, St. Paul, Minn. 



Figs. 22 to 25. EHINIDICTYA NEGLECTA n. sp 130 



22. A fragment of the natural size and a portion xis, showing the usual characters of the 



species . 



23, 24 and 25. Eespectively, trarsverse, vertical, and tangential sections of a specimen wider 

 . than the original of flg. 22, but agreeing in all other respects with it. 



Trenton limestone near Danville, Ky. 



