Thirty-eight specimens collected along the intertidal zone from the southern Pacific of Mexico were examined, resulting in the extension of the distribution ranges for Eucinetops lucasii Stimpson, 1860 from Mazatlán, Sinaloa to San Agustín Bay, Oaxaca (approximately 1488 km southward), E. rubellulus Rathbun, 1923 from Maruata, Michoacán to La Tijera Beach, Oaxaca (802 km southward), and Uca musica Rathbun, 1914 from San Blas, Nayarit to La Encrucijada Biosphere Reserve, Chiapas (1763 km southward).