PLATE XLIII 



PAGE 



Figs. 1-7. HOMALONOTUS DEKAYI ( Green) 328 



1. A young, distinctly trilobate and nearly entire individual. 



2. An enrolled and uncompressed individual. 



3. The hypostoma. 



4. An enlargement of the under surface. X 5. 



Hamilton formation, New York. 



5. Dorsal view of a pygidium. 



6. A smaller and somewhat crushed pygidium, showing the reflexed 



apex. 



7. An enlargement of a portion of the surface of same. X 10. 



Romney formation, Hamilton member, road east of Pine Hill, 

 about 4 miles north of Oldtown. 



Figs. 8-12. PHACOPS RANA (Green) 329 



8. Dorsal view of cephalon. 21st Bridge. 



9. The eye of same. X 3. 



10. Pygidium. X 2. Evitts Creek. 



Romney formation, Hamilton member. 



11. A small individual. 



12. The eye of a slightly weathered specimen enlarged. 



Hamilton formation, New York. 



Figs. 13-15. PHACOPS CBISTATA Hall 331 



13. Cephalon and part of the thorax of an enrolled specimen, showing 



axial and genal spines. Alinda, Penna. 



14. Lateral view of an enrolled specimen with a partly crushed gla- 



bella, showing genal spine base. Alinda, Penna. 



15. Fragmentary thorax and pygidium, showing axial spines. Ridge- 



ville, W. Va. 

 Romney formation, Onondaga member. (After Kindle.) 



Figs. 16, 17. PHACOPS CRISTATA VAR. PIPA Hall 332 



16. Fragmentary enrolled thorax. Alinda, Penna. 



17. Pygidium, showing duplicate character of pleural anntilations. 



Near New Bloomfield, Penna. 



Romney formation, Onondaga member. (After Kindle.) 



126 



