Twenty-two localities, where unpigmented and mostly blind tricladid turbellarians (Dendrocoelidae and Fonticola) were discovered by the author, are described in more or less detail. These animals are particularly well represented in Romania; the explanation is that they are expansive offshoots of a fauna formerly inhabiting the huge brackish or freshwater lakes which covered most of this country during the Neogene (and especially the Sarmatian). Different species are inhabitants of different particular habitats of the underground water realm, and the author distinguishes between species inhabiting cave waters, typical phreatobionts, hyporheic species and species living in springs or springbrooks. These species are sensitive indicators of even small changes affecting the abiotic or biotic conditions prevailing in their habitats (several examples are offered, especially of competitive exclusion).