Abstract
A new space-voltage clamped giant (500 to 900 microns) axon preparation is described (Myxicola infundibulum). Normal value for resting and action potentials are 71 and 89 millivolts, respectively. This preparation under voltage clamp exhibits relations between current and voltage like those described for the squid axon. The early inward current component is reduced in a solution with low sodium concentration. This preparation, then, acts in all its essential features like the squid giant axon. Myxicola, however, can be made available the year around and should prove to be an extremely useful preparation for the study of excitable membranes.