Motility of wild-type and phenamil-resistant strains in M agar containing 300 mM NaCl and 40 μM phenamil after 10-hr incubation. Relative rates of expansion were normalized to the expansion rate of LM4609. The normalized rates are: LM4616 (0.8 ± .07), LM4641 (1.04 ± .03), LM4647 (0.90 ± .03), LM4629 (1.8 ± .18), LM4613 (1.23 ± .09), LM4606 (1.27 ± .03), LM4603 (1.11 ± .06), LM4614 (.81 ± .05), LM4609 (1.0 ± .05) LM4639 (1.0 ± .07), and LM4598 (1.0 ± .12).