Abstract
Well preserved calcimicrobes and microbialites are found from the Lower Devonian Fukuji Formation in the Hida "Gaien" Terrane. Calcimicrobes occur with skeletal metazoans and intergrow to form unique microfacies together with varied microbialite fabrics. Microbialites were ubiquitous and largely contributed to limestone formation. Research into calcimicrobial compositions and microbialites is indispensable to elucidate the biotic diversity and palaeoecological conditions at that time.