Help with Ancient Maya Offering Shells

[paul monfils]

Hi James,
#1 is a Nerita (family Neritidae).  Not sure of the species.
#2 is Cittarium pica (family Trochidae), a common shallow water Caribbean species.
#3 is Cyphoma gibbosum (family Ovulidae), common Caribbean species. Glossy orange when fresh.
#4 is a bivalve, too damaged to be certain even of the family

Just noticed your web address - brown.edu.  I'm in Providence!