Pharate jaws of the Ordovician and Silurian Eunicida have been studied under a scanning electron microscope and the conjecture has been formed that the molting of jaws in the Early-Paleozoic Eunicida took place many times in the process of their ontogeny and was not necessarily connected with their growth. The cases of jaw replacement, observed so far in the fossil Polychaeta, were of the nature of a cyclic physiological regeneration, whereas the replacement of jaws in Recent forms is a reparative regeneration. The specific name Mochtyella multilamellata Szaniawski 1970 is a simultaneously published synonyme of the name Mochtyella fragilis Szaniawski 1970, accepted as a valid.