The distribution, ecology and systematics of the lunulitiform bryozoans of Una Grande (RJ) region are studied. The occurrence of the species is correlated to the granulometry of the sediment and depth. Disaopopella umbellata does not occur in silt-clay bottoms. Cupuladria biporosa was found in deeper stations than Discoporella umbellata. This species occurs in highest density than the former.