Diagram of the sutures of Ammonites: A, an elaborate suture (Phylloceras); B, a simple suture (Ceralites); s,s, siphonal; s,v., ventral; s.l., first lateral; s,l', second lateral saddles; t.v. ventral; l, first lateral; l', second lateral loce; La,la, aux

Freshwater and Marine Image Bank, University of Washington Libraries Digital Collections