PLATE LXXI 



PAGE 



Figs. 1-3. STYLIOLINA FISSURELLA (Hall) 685 



1. Surface of fragment of shale covered with shells, natural size. 



2. Fragment enlarged. X 3. 



3. Single individual. X 6. 



Genesee formation, New York. 



Figs. 4-6. COLEOLUS TENUICIXTUS Hall 687 



4. Cast of interior of shell of unusually large size. Maryland-Pennsyl- 



vania state line, east of Ragged Mountain. 



5. 6. Apices of two specimens. X 6. One-half mile north of Pawpaw. 



Jennings formation, Parkhead member. 



Figs. 7-9. HYOLITHES ACLIS Hall 688 



Three views of cast of interior. X 2. Jennings formation, Parkhead 

 member, Sideling Hill Creek, 2 l / 2 miles above mouth, 1700. 



Fig. 10. PHARETREIXA TENEBROSA Hall 690 



Specimen showing ornamentation. Genesee formation, New York. 



Fig. 11. BACTRITES ACICTJLUS (Hall) 692 



A specimen showing the usual crushed and incomplete condition of the 

 fossil. Jennings formation, Genesee member, Williams Road, 

 near Cumberland. 



Figs. 12, 13. ORTHOCERAS FILOSUM Clarke 691 



Specimens showing the surface characteristics. Jennings formation, 

 Woodmont member, Naples fauna, Town Creek, Gilpin. 



Figs. 14, 15. ORTHOCERAS DEMUM Hall 691 



14. Chamber of habitation. 



15. A part of shell showing septa. 



Jennings formation, Chemung member, National Road, east of 

 Hancock, 2223. 



Figs. 16-18. ORTHOCERAS CONSORTAI.E Hall 690 



16. Cast of a portion of shell showing septa. 



17. Portion of shell showing chamber of habitation. 



18. Septum showing siphuncle. 



Jennings formation, Chemung member, Williams Road, Polish 

 Mountain, 2043. 



154 



