QQ PROCEEDINGS OF THE NATIONAL MUSEUM vol.68 



Page 



Fig. o. Polygnathus folium, new species 46 



Upper surface of plate, showing irregular leaf-shaped out- 

 line. 



6. Polygnathus rhomhoideiis, new species 46 



Upper side of plate exhibiting rhombic outline. 



7. Ancyrodclla haniata, new species 48 



Upper surface of the harpoon shaped plate. 

 8. Polygnathus pennatulus, new species. (See also pi. 9, figs. 24, 25)- 45 

 Profile, top view and cross section of the type specimen. 



9, ]0. Polygnathus delicatulus, new species 45 



Upper surface of two examples. 



11, 12. Polygnathus germanus, new species 40" 



Top and edge views of the type specimen. 



13. Polygnathus glaher, new species 46 



Top of plate showing smooth surface. 



14.15. Polygnathus confluens, new species 46 



Upper and lower surfaces of two examples. 



16, 17. Palmatolepis hifurcata, new species 50 



Lower and upper surfaces of separate specimens. 



18. Palmatolepis asymmetrica, new species 50 



Upper surface of this unsymmetrical plate. 



19-23. Palmatolepis perlobata, new species _ 49 



Five specimens — two (19, 21) siiowing lower surface, two 

 (20, 22) the upper surface, and one (23) representing pos- 

 sibly a variation. 



Plate S 



All the illustrations on this plate are magnified 15 diameters. The specimens 

 are from the Hardin sandstone basal member of the Mississippian-Chattanooga 

 black shale at Mount Pleasant, Tenn. 



Pago 



Fig. 1. Ancyrodclla symmetrica, new species 49 



Upper surface showing symmetrical arrangement of orna- 

 ment. 



2, Polygnatluis sublatus, new species 47 



Upper surface illustrating arrangement of tubercular orna- 

 ment. 



3. Palmatolepis extralohata, new species 51 



Under surface of the type specimen. 



4, 5. Polygnathus acaulis, new species 47 



Upper and lower surfaces of two plates exhibiting absence 

 of stalklike projection. 



6, 7. Polygnathus concentricus, new species 47 



Upper and lower surfaces of two plates showing the orna- 

 mentation. 



8-10. Polygnathus crassulus, new species 48 



Lower, edge, and top views of the same specimen. 



11,12. Palmatolepis peculiaris, new species 51 



Upper surface of opposite plates. 



13. nindeodella dccurrens, new species 40 



The type specimen showing the characteristic downward 

 curving of the anterior portion. 



