Abstract
Both sexes of Heterolaophonte uncinata (Cherniavski, 1868) and H. curvata (Douwe, 1929) are redescribed based on newly collected material from the Black Sea and Mediterranean coasts of Turkey in view of the fact that there has been no detailed redescription since their original descriptions. Neotypes are also designated for both species. Detailed comparisons of the characters displayed among Heterolaophonte Lang, 1948 species reveal that the genus cannot be defined by any unique apomorphy. We propose that the structure of the male appendages, especially the swimming legs, can provide a considerable number of significant characters that are valuable both for taxonomic identification and phylogenetic inferences. In addition, several mistakes leading to a great confusion in the accurate interpretation of the relationships among species within Heterolaophonte are discovered in earlier species descriptions. Therefore, H. rottenburgi (T. Scott, 1912), H. exigua (T. Scott, 1912), H. australis (T. Scott, 1912), and H. insignis (T. Scott, 1914) are removed from the genus and placed as incertae sedis in Laophontidae. We also conclude that H. phycobates (Monard, 1935), H. pygmaea (T. Scott, 1893), H. tupitskyi Chislenko, 1976, and H. curvata micarthros Marcus & Por, 1960, which still need further taxonomic investigation, have doubtful identity within the genus, and we place them as species inquirendae.