Abstract
The new species is described in detail. It lacks eyes, has saddle-shaped nuchal organs, and reproduces throughout the year. Some new morphological details are given for M. aberrans (WEBSTER & BENEDICT, 1885) and M. sczelkowii MECZNIKOV, 1865. All three species possess two types of neurosetae, composite and simple transitory. While the number and position of the testes is fairly constant in M. ephippiophorus and M. sczelkowii, great variation is found in M. aberrans. The excretory organs are bifurcated in M. aberrans, but unbranched in the other species. They appear to be modified metanephridia with protonephridial characteristics. The new species is considered to be closely related to M. arenarius WESTHEIDE, 1973, M. sczelkowii, and M. southerni WESTHEIDE, 1967. Some notes on ecology are given.
