Porcellana lillyae, new species (Decapoda, Anomura, Porcellanidae), from the Caribbean Sea, with a key to the western Atlantic species of the genus

A new species of porcelain crab, Porcellana lillyae, from the continental s helf of the Caribbean coast of Colombia, is described. This new species, th e fourth of the genus Porcellana Lamarck currently recognized from the west ern Atlantic, is most similar to P. sigsbeiana A. Milne-Edwards. The new sp ecies is distinguished primarily by the dentate condition of the frontal an d lateral margins of the carapace and the presence of spines on the ventral margin of the rostrum. The new species is compared with P. sigsbeiana, and a key to aid in identification of western Atlantic species of the genus is presented.