PLATE V. 
Figs. 1 to 10. PHYLLOPORINA CORTICOSA UIP.... 1.2. 0s. ee eee eee tener e eet terete eee ene eens 212 
1. A frond of this species exposing the poriferous or obverse side; natural size. 
2and 6. Reverse side of a fragment, natural size and a portion “9. 
3and 7. Obvyerse side of another fragment, natural size and a portion <9. 
4and 5. Two specimens of the basal portion of the zoarium, natural size. 
8. Tangential section, X18, cutting the zocecial tubes at varying depths from the surface. 
9. Transverse section of several branches, 15. ; 
10. Vertical section of a branch, <18. 
Upper third of the Trenton shales, near Cannon Falls, Minn. 
Figs ll and 12. MRHINIDICTYA GRANDIS, N. SP......-- ses eee ee eee eee e eee teen ence tees twee cece 136 
A fine example from the ‘Lower Blue” limestone at DixonII1., natural size and a portion 
x9. (See also Plate VI.) 
Figs. 138 to 18. RHINIDICTYA MINIMA Ulr..............-...- gos einibie fiee/6\a\e\sfelele nisinin/sjn\s/eleislnibialeis/a aloisic/sisiel= 132 
13. Three fragments of the natural size. 
14and 15. One of them x9, and a portion of same <18, showing the small zooscial apertures 
and grano-striate character of the interspaces. 
17. Tangential section of the variety MODESTA, X18, showing the appearences of the zowcia 
at various depths beneath the surface. 
18. Tangential section of the typical form of the species, *18. 
Upper part of the Galena shales, near Cannon Falls, Minn. 
Wigs. 19 to 21. REINIDICTYA PAUPBRA UlP.. 2.00.0 csc c cece eee ee ees came teenies cence cena cieiele 129 
19. A nearly complete specimen, natural size. 
20and 21. A fragment, natural size <9 and X18. 
Upper third of the Trenton shales, St. Paul, Minn. 
Figs. 22 to 25. RHINIDICTYA NEGLECTA DN. SP... eee. ee eee cee eee cette te eee e eet teen eee e eens cees 130 
22. A fragment of the natural size and a portion X18, showing the usual characters of the 
species . 
23,24 and 25. Respectively, trarsverse, vertical, and tangential sections of a specimen wider 
than the original of fig. 22, but agreeing in all other respects with it. 
Trenton limestone near Danville, Ky. 
