AbstractThe eyestalk musculature ofPandalus danae, Palaemon malcolmsonii, Penaeus indicus, Panulirus polyphagus, Astacus fluviatilis, Hippa asiatica, Diogenes miles, Paratelphusa guerini, Callinectes sapidusandSquilla harpaxhas been dealt with. The eyestalk consists of three segments, the proximal, the middle and the distal segments, in all the species. There is only one basal muscle, the anterior basal muscle, attached to the proximal segment of each eyestalk. The anterior and the posterior basal muscles can be grouped into three types, called the macrurous, the anomurous and the brachyurous types. The attractor muscles are intrinsic in the macrurous types, extrinsic in the brachyura and absent in the anomura. In the Reptantia the adductors are disposed along the long axis of the eyestalk while in the Natantia they lie across the axis.