The influence of continuous and differential transitory starvation on the moult cycle and morphogenesis of H. araneus L. larvae was studied in laboratory experiments. Larvae starved from hatching (zoea I) or from moulting to later instars (zoea II, megalopa) develop, independently of food supply, to Stage C (intermoult). Postmoult Stages (A and B) and parts of intermoult are completed by utilizing internal body reserves under such conditions but cuticle formation is terminated at an advanced but incomplete stage within intermoult. In the zoea-II instar there is morphogenesis in appendages (pereiopod and pleopod buds) during continuous starvation. This supports the hypothesis that moult cycle and morphogenesis may be partly independent processes which are normally synchronized.