Abstract
Sicyopus leprurus and Lentipes armatus are described as new species of the Sicy-diaphiinae, Gobiidae, from a hill stream on Ishigaki Island, Ryukyu Islands, Japan.They are distinguishable from other species of each genus mainly in their squamation.Morphological comparison of four genera and six species of hill-stream sicydiaphiine gobies suggests that Sicyopterus is the highest and Sicyopus is the lowest in the degree of adapta-tion to torrential environments, Lentipes and Stiphodon are intermediate between Sicyopterus and Sicyopus.
