PLATE VII. 

 Phacops rana. 



Page 19. 

 See Plates 6, 8, 8 a, and 25. 

 Fig. 1. A specimen of average size, retaining the crust, and showing the general characters of the 

 species. 



Hamilton shales. Geneseo, Livingston county. 

 2. A somewhat smaller specimen, retaining the parts in juxtaposition. 

 Hamilton shales. Eighteen-mile Creek, Erie county. 

 Fig. 3. Anterior view of a large, enrolled individual. 

 Fig. 4. Posterior view of the same. 



Hamilton shales. Canandaigua Lake. 

 Fig. 5. Anterior view of a still larger, enrolled specimen. 



Hamilton shales. Darien, ffenesee enmity 

 Fig, >'>. A somewhat imperfect eephalon of a very large individual. 



Hamilton shales. Near Geneseo. Livingston county. 

 Fig. 7. A specimen showing two individuals of nearly equal size, lying one upon the other. 

 Fig. S The same, with the upper individual removed. The emarginate outline of the pygidium in the 

 lower specimen is due to compression, and the sulci represented on the annulations of the left 

 pleura do not exist. 



Hamilton shales. Canandaigua Lake. 

 Fig. 9, A large individual partly restored on the left side. 



Hamilton shales. Canandaigua Lake. 

 Fig, 10. A very large, entire individual. This is the largest entire specimen yet observed. 

 Fig 1 1. Profile of the same, showing the glabella flattened from compression in the shales. 

 Hamilton shales. Canandaigua Lake. 



