In general, the locomotry pattern of Decapod Crustacea can be regarded as representing the evolutionary old type of crosswise activation of ambulatories. In the highly evolved fiddler crabs of the genus Uca (Osypodidae) this old locomotory pattern can still be traced though some of the ambulatories play a prominent role in the display parade, i. e., have become part of a different apparatus. While in all Uca species the chelipeds are used in waving, the extent of activating one or more pairs of ambulatories in display movements varies from species to species. Alternatively, waving the chelipeds is strictly correlated with locomotion in some species, while it has become almost fully independent from locomotion in others. This degree of correlation, viewed as neurophysiological interrelation of locomotion and display, seeros to be an (additional) indicator of the evolutionary level of Uca species. Based on motion picture analyses of several Old and New World forms of Uca the present paper reports the relevant findings on the Indian species Uca vocans ( "marionis) and U. annulipes