Larval development of the spider crab, Libinia emarginata, consists of two zoeal stages and megalopa. Laboratory-reared larvae (South Carolina and Rhode Island) are described and compared with planktonic larvae from Narragansett Bay, RI. No significant variations in morphology were found between laboratory-cultured larvae and 'wild' larvae from plankton catches: first stage zoea from South Carolina were smaller than Rhode Island specimens. Using Artemia diets, the best percentage survival in culture was found to be 20C for Rhode Island larvae and 25C for South Carolina larvae. Zoeal stages show little difference from larvae of L, dubia; however, the megalopae of the two species can be differentiated by the number of protuberances on the cardiac region of the carapace.