PLATE CXXIII. 



GOMPHOCEKAS GOMPHUS. 



Page 32. 

 Fig. 1. Lateral view, showing the air-chambers, undulations of the tube, the crenulated zone, and cham- 

 ber of habitation. Some of the crenulations are seen extending over the walls of the chamber 

 on the right side of the figure. The impression of the ventral valve of a Crania is preserved 

 upon the chamber of habitation. 



Comiferous limestone. Delhi, Delaware county, Ohio. 



GOMPHOCERAS MANES. 

 Page 34. 



Fig. 2. View of the specimen described, showing its extremely compressed condition, and the depth of the 

 air-chambers. The surface shows several branches of polyzoa and young brachiopods which 

 were probably attached to the shell. 



Genesee slate. South of Allien, Erie county. 



