Abstract: The species of Donacosmilia corallina de Fromentel (hermatipic coral) have been defined as Upper Jurassic (Oxfordian-Kimmeridgian, Portlandian ? ) in age by most European research workers. The presence of this form has also been noted from the reefal limestones of Yukarıköy formation in the Araç-Daday (Kastamonu) region of Turkey. In this study systematic description of this formis presented and the associated reefal limestones are assigned to Upper Jurassic (Upper Oxfordian-Lower Kimmeridgian) in age.