Hi, from again hot St. Louis (90 degrees todat) On a bivalve, is "height" the measurement from dorsal to ventral? Is "width" the measurement of the widest part at right angle to "height," between anterior and posterior? O.K., then, what is the term for the thickness of shell, measured between right and left valve at its greatest distance, measured at a right angle to the plane defined by the separation lines of the valves; would this be "depth?" Thanks, Linda