Leschkes' test was performed on the cuticle samples of Ocypode platytarsis, Metapenaeus monoceros, Emerita asiatica and Ligia exotica. Gill cuticle appeared to be markedly permeable to ions. The cuticle lining the gut in Ocypode platytarsis and Metapenaeus monoceros was also permeable, but to a lesser extent than the gill cuticle. The body cuticle of Ocypode platytarsis and Metapenaeus monoceros do not show permeability to Chloride. Permeability of the cuticle samples to water was tested by the dye penetration technique. It was noted that gill cuticle was markedly permeable. Next in degree of permeability was the cuticle lining the gut in Ocypode, Metapenaeus and Emerita. The body cuticle in all the three animals namely Ocypode, Emerita and Ligia was impermeable to dyes. In Metapenaeus the intermoult body cuticle showed permeability to water.