PLATE VIII. 



PAGE. 



Figs. 1-2. Linguea ligea Hall 462 



1. View of a spec men from the Huron Shales at Delaware, Ohio. 



2. The same enlarged to show muscular imprints. 



Fig. 3. Orthis Tioga Hall 453 



3. View of a concretion containing valves of two individuals, natural size. 



Figs. 4-5. Pal^Eoneilo simieis Whitf. .. 453 



•1 Side view o: the specimen described, natural size. 



5. Cardinal view enlarged showing impressions of teeth 



Figs. 6-11. Plumueites Newberryi Whitf 463 



6. A small plate of the prevailing form. 



7. An elongated plate probably from near the extremity of the body. 

 8-10. Three plates showing as many forms. 



11 View of a conical plate which overlies a second, from a concretion. 



Figs. 12-14. Echinocaris sublevis Whitf. 457 



12. View of one side of a concretion showing a part of a valve and the abdomen and 



telson of this species, natural s ze. 



13. View of the left side of a carapace as taken from the oiher half of the same concre- 



tion as Fig. 12, enlarged. 



14. The abdomen and telson enlarged from the specimen Fig. 12 



Fig. 15. Echinocaris pustueosa Whitf 458 



15. The right valve of a carapace enlarged. 



Fig. 16. Echinocaris muetinodosa Whitf 458 



1(5 Dorsal view of both valves of a c-irapace, natural siz;. 



Figs. 17-18. Aristozoe Canadensis Whitf 467 



17. Dorsal view of the specimen described, natural size. 



Is. Lateral view of the same showing the three rows of small pustules near the basal 

 margin. 



Figs. 19-21. Pal.Eopal.Emon Newberryi Whitf. 461 



19. Lateral view of the specimen enlarged to two diameters, showing the parts de- 



scribed. 



20. Posterior view of the last abdominal segment and telson as seen on the specimen, 



in impression of the under surface. 



21. View of the upper surface of the same as obtained from the matrix by gutta-percha 



both enlarged as Fig. 19 The figures indicate the different elements of the 

 caudal flap. 



