EXPLANATION OF PLATE XLVIII. 



TRIGONIA THORACICA Morton, p. 460 



1-2. Views of a left and a right valve. 



Marshalltown clay-marl; near Swedesboro, (/77). 

 3-4. Two views of an internal cast. The type of T. mortoni 

 Whitf. 



Navesink marl; Freehold. 



TRIGONIA EUFAULENSIS Gabb, p. 462 



5. View of an internal cast. 



Wenonah sand; near Marlboro, (/jo). 



6. View of an internal cast. 



Merchantville clay-marl; Lenola, (163). 

 7-8. Two views of a complete individual from Alabama. (Coll. 



U. S. Nat. Mus.) 



9-10. Internal and external views of a left valve from Alabama. 

 (Coll. U. S. Nat. Mus.) 



TRIGONIA K^MMELI n. sp., p. 466 



11-12. Views of two left valves, plaster casts taken from natural 

 moulds of the exterior. 



Red Bank sand; Shrewsbury River, (116). 



TRIGONIA CERULIA Whitfield, p. 464 



13. View of a left valve from the type locality. 



Tinton beds; Beers Hill Cut, (129*). 



978 



