Cryptonatica adamsiana (Dunker, 1860), a naticid species found only in Japan waters, is surprisingly collected from a coastal flat in west-central Taiwan. The species is recorded for the first time from theTaiwanese coastal flats. Fifteen specimens in varies life stages were collected in the present study; therefore, the ontogenetic changes in shell coloration is herein noted. In addition, the taxonomic status of naticid species known from Taiwan is also discussed.