New species and records of < italic > Cloeodes Traver, 1938 (Ephemeroptera, Baetidae) from Costa Rica

The nymph of Cloeodes danta sp. nov. is described from male and female nymphs collected from highland streams in the Caribbean Slope of the Costa Rica Central Volcanic Mountain Range. Adults are unknown. In addition, C. excogitatus and C. redactus are recorded for the first time in the country. Cloeodes danta sp. nov. can be differentiated from all described species by the predominantly brownish coloration on females and a similar coloration on males but with segments VII-IX light yellow and light brown, with no conspicuous marks or patterns; abundant scale-bases throughout most parts of the body; hindwings pads absent; the presence of three spines in the corners of the posterior margin of sternum III, and the posterior margin of tergum III with 28-30 spines on each side of the middle line (spine with a base width up to 0.5x spine length).