"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…