Abstract
Selected internal and external structures of the head of larvae of Hydrotrupes palpalis Sharp are examined, described and interpreted phylogenetically. The results suggest a sistergroup relationship between Hydrotrupes and the remaining Dytiscidae excl. Copelatini. Therefore, Hydrotrupes should be excluded from Colymbetinae. The sistergroup relationship between Copelatini and all other Dytiscidae is confirmed.