EXPLANATION OP PLATE XLII. 



Ammonites Vanuxemi Morton (p. 253). 



Figs. 1, 2. Lateral and dorsal views of Dr. Morton's type. 



3,4. Profile aod lateral views of a larger specimen from the collection of tUe Am. Mus. Nat. 

 History. 

 5. An enlarged outline (2x) of a septum from the outer portion of the last specimen. 



Ammonite^ Delawarensis Morton (p. 252). 



6,7. Lateral and dorsal views of a small specimen, showing the narrow volution in strong 

 contrast with Fig. 4. 



8. Lateral view of a larger specimen. Bot.h are from the Acad. Nat. Sciences collection. 



9. Diagram, natural size, of the species from the specimen figured on PI. XLiii, and allowing 



strong contrast with Fig. 5. 



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