PLATE VIII. 

 Phacops rana. 



See Plates 6, 7. 8 a, and 25. 

 Pig. I. A young individual, enrolled and showing two pairs of lateral furrows upon the glabella. 

 Fig-. 2. Profile view of the same. 

 Pig. 3. Front view of the same. 



Hamilton group. Moscow, Livingston county. 

 Fig. 4. Profile view of a small eephalon, Bhowing normal proportii 

 Pig. 5. Dorsal view of the same, showing the glabellar furrows. 

 Fig. 6. An eye of the same enlarged. 



Hamilton group. Eighteen milt Oreek, Er'u county. 

 Kilt. 7. A young, enrolled individual, showing the glabellar furrows. 



Hamilton group. Eighteen-mile creek, Er'u county. 

 Pig. 8. Profile view of an enrolled, slightly crushed specimen. 

 Fig. 9. Dorsal view of the same. 



Hamilton group. Widder; Province of Ontario. 

 Fig. 10. A larger, enrolled individual. 



Hamilton group. Canandaigua Lake. 

 Fig. 11. A nearly entire, young individual. 



Hamilton group. Darieri, Gferies'ee county. 

 Fig. 12. The eye of a small individual, enlarged to three diameters, showing- more numerous lenses than 

 in advanced stages of growth. 



Hamilton group. Eightet n-uiili Creek, Erie county 

 Pig. 13. The eye of a larger individual, showing fewer lenses (similarly enlarged). 



Hamilton group. Oeneseo, Livingston county. 

 Fig. 14. The eye of a slightly weathered specimen, showing the cavities left by the removal of the lenses 

 (similarly enlarged). 



Hamilton group. Near Gfeneva, Ontario county. 

 Fig. 15. An obliquely compressed ami distorted specimen, showing a common mode of occurrence, 



Hamilton group. Canandaigua hake. 

 Fig. 16. A large, entire eephalon. 

 Pig. 17. Profile view of the same. 



Hamilton group. Canandaigua Lake. 

 Fig. 18. A fragment of the under side of the eephalon, showing a portion of the hypostoma in place. 



Hamilton group. Jaycox's Rim, near Gfeneseo, Livingston county. 



Phacops Cacapona. 

 Page 27. 

 Fig. 19. Dorsal view of a somewhat worn internal east in chert. 



Hamilton group. Mouth of the Cacapon river, Virginia. 

 Fig. 20. Profile of another example, similarly preserved. 

 Fig. 21. Dorsal view of the same. 



Hamilton group. Mouth of tin Cacapon rim: Virginia. 

 Fig. 22. Front view of an enrolled specimen, referred with some hesitation to this specie 

 Fig. 23. Dorsal view of the same. 

 Fig. 24. Profile view of the same. 



Hamilton group. Locality doubtful. 



