56 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.68 



Plate 2 



Illustrations all magnified 15 diameters and specimens are from the Rhine- 

 street shale of the Portage group at Slialeton, Erie County, N. Y. 



Page 

 Fro. 1, 2. Ligonodina panderi Hinde, 1879 13 



(1) Pander's drawnig of his type. 



(2) A young specimen referred to the species. 



3,4. Ligonodina deflecta, new species ]3 



Two teeth, representing outer and inner sides, showing the 

 characteristic curvature of the base in the posterior half. 



5,6. Ligonodina magnidens, new species 14 



Teeth of opposite sides exhibiting the large size of the 

 denticles. 



7,8. Ligonodina liibhardi, new species 14 



A young and a mature example, opposite sides. 



9,10. Ligonodina pectinata, new species 13 



Two examples, the first nearly complete, illustrating the 

 comb-like arrangement of the denticles. 



11-13. Ligonodina falciformis, new species 14 



(11, 12) Two fairly complete teeth showing the backward 

 slant of the denticles. 



(13) Another example in which the carina of the main cusp 

 and the suckerlike protuberances of its downward exten- 

 sion are well shown. 



14-16. Ligonodina hindei, new species 14 



(14) An incomplete example preserving well developed 

 downward extension. 



(15, 16) Two specimens illustrating the same side but right 

 and left, showing relationship to L. panderi but differing 

 in the recurving of the main cusp and denticles. 



Plate 3 



Specimens here illustrated are from the Rhinestreet shale at Shaleton, 

 N. Y., and illustrations are magnified 15 diameters. 



Page 



Fig. 1-i. Hibbardella angulata Hinde, 1879 37 



(1,2) Two examples regarded as typical. 



(3) A variety with the main cusp broad, more sharp 



edged and relatively shorter than others. 



(4) A specimen illustrating length of medium cusp of 



this or a similar species. 



5. Eibbardella? confertissima, new species 38 



The type specimen of this minute species. 



6,7. Hihbardella subequalis, new species 38 



Two specimens, one (7) a mold in the rock, illustrating 

 the short main cusp and the thick bar. 



8,9. Hibhardclla mnltidenfi, new species 38 



Two examples showing the wide angle made by the two 

 ends of bar and the numerous denticles. 



10. Euprioniodinu perangulata, new species 30 



The holotype showing great development of the down- 

 ward projection. 



