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"Having a sinuous pallial margin and consequent sinuous impression on the shell along the line of attachment of the mantle. Into the sinus thus formed the siphons, which are always developed in these bivalves, can more or less be withdrawn." —Whitney, 1889

Iphigenia Brasiliensis - Sinupalliate Right Valve

"Having a sinuous pallial margin and consequent sinuous impression on the shell along the line of attachment…

"Several Forms of Bivalves. A, Avicula; B, Pectunculus, with extended foot (a); C, Venus, with respiratory siphons (a, b) and extended foot (c); D, Mya truncata, showing respiratory siphons (a, b) and foot (c)." -Vaughan, 1906

Forms of Bivalves

"Several Forms of Bivalves. A, Avicula; B, Pectunculus, with extended foot (a); C, Venus, with respiratory…