New species of Mermithidae (Mermithidae, Nematoda) from Estonia and neighbouring regions. 10. The genera Pseudomermis, Lanceimermis and Limnomermis. Eesti NSV Teaduste Akadeemia Toimetised Bioloogia, 31(1) 1982: 7-14. 13 [Zoological Record Volume 119]