Morphological examination and molecular analyses of specimens of the genus Limacia collected in the Eastern Pacific Ocean indicate that four species of Limacia occur in the region. Limacia cockerelli, previously considered to range from Alaska to Baja California, is common only in the northern part of its former range. An undescribed pseudocryptic species, previously included as L. cockerelli, occurs from Northern California to the Baja California Peninsula and is the most common species of Limacia in Southern California and Northern Mexico. Another new species similar to L. cockerelli is described from Antofagasta, Chile and constitutes the first record of the genus Limacia in the Southeastern Pacific Ocean. These two new species are formally described herein. Finally, Limacia janssi is a genetically and morphologically distinct tropical species ranging from Baja California to Panama. Species delimitation analyses based on molecular data and unique morphological traits from the dorsum, radula, and reproductive systems are useful in distinguishing these species