This chapter provides a brief taxonomic conspectus of the Japanese
nemerteans with photographs of 100 species. A total of 126 species are recognized
in Japanese waters, but there are still at least 77 unreported/undescribed forms
awaiting formal description. Previous records of 4 species (Amphiporus gelatinosus
Coe, 1905; Cerebratulus longiceps Coe, 1901; Cerebratulus montgomeryi Coe,
1901; and Emplectonema buergeri Coe, 1901) are regarded to be unsubstantiated.
The names of the 3 species Cerebratulus penniger Iwata, 1957, Euborlasia proteres
Iwata, 1957, and Lineus nipponensis Senz, 2001 are treated as nomina dubia. The
following 6 are herein judged as junior synonyms of older names: Amphiporus
insolitus Iwata, 1954 [=Diplomma serpentina (Stimpson, 1855)]; Amphiporus
reduncus Iwata, 1957 and Amphiporus retrotumidus Iwata, 1957
[=Nipponnemertes ogumai (Yamaoka, 1947)]; Cerebratulus albocirculus Iwata,
1957 [=Lineus albovittatus (Stimpson, 1855)]; Cerebratulus fasciatus Stimpson,
1857 [=Notospermus geniculatus (Delle Chiaje, 1828)]; and Tetrastemma
yamaokai Iwata, 1954 [=Tetrastemma roseocephalum (Yamaoka, 1947)]. Five
species are herein added as new members of the Japanese nemertean fauna:
Cerebratulus rubellus (Stimpson, 1855); Cerebratulus signatus Coe, 1905;
Micrura callima Sundberg and Gibson, 1995; Tetrastemma pimaculatum
Chernyshev, 1998; and Tortus tokmakovae Chernyshev, 1991.