I.N. Filipiev's book "Free-living marine nematodes of the vicinity of Sevastopol" is a fundamental study of marine nematodes living in the area of Sevastopol. The work was published in two editions: the first in 1918, the second in 1921. First issue (1918): Title: "Free-living marine nematodes around Sevastopol. Issue 1" Volume: [4], 350, [1] pages, 11 pages of illustrations Contains a detailed description of the morphology, biology and ecology of free-living marine nematodes living in the shallow waters of the Crimea and adjacent salt estuaries. Particular attention is paid to rare species, their conditions of existence, role in ecosystems and trophic relationships. Second issue (1921): Title: "Free-living marine nematodes around Sevastopol. Issue 2" Volume: XII, 353-614 pages, illustrations Content: Continues research of the first release, providing additional data and descriptions of new species. Includes bibliography on pages 514-515, 560-562, 573-594. Both issues were published by the Russian Academy of Sciences in the series "Works of the Special Zoological Laboratory and Sevastopol Biological Station." The first issue was reported at the meeting of the Department of Physical and Mathematical Sciences on November 26, 1914. These works are significant contributions to the study of marine nematodes and are still used by researchers in marine biology and zoology.