The subgenus Dermomurex (Takia) is reviewed and one new species, D. (T.) manonae n. sp., is described from New Caledonia. It is distinguished from the similar D. (T.) wareni Houart, 1990 based on genetic differences and a few shell characters. From other species it differs in its shell and intritacalx morphology. The four Indo-West Pacific species are reviewed and illustrated, namely D. (T.) bobyini Kosuge, 1984, D. (T.) infrons Vokes, 1974, D. (T.) wareni Houart, 1990 and D. (T.) manonae n. sp. Dermomurex (subgenus?) paulinae n. sp. is described from New Caledonia in an undetermined subgenus and is distinguished from D. (D.) africanus Vokes, 1978 from South Africa by its shell and intritacalx morphology. Trialatella is synonymized with Dermomurex s.s.

A new unionid species Lanceolaria kihirai n. sp. is described from the Futatsukawa Creek, Yanagawa City, Fukuoka Prefecture and the Matsuura River, Karatsu City, Saga Prefecture, Kyushu, Japan. L. kihirai n. sp. differs from L. triformis and L. lanceolata in having a non-twisted shell, and from L. oxyrhyncha and L. grayii in having a round posterior ridge. Moreover, the posterior ridge is prominent from beak to the posterior end in L. oxyrhyncha, L. grayii, L. gladiola and L. acrorrhyncha, while gradually becoming obscure toward the posterior end in L. kihirai n. sp.

The structural composition of shells was observed by scanning electron microscopy for one amathinid and five pyramidellid species in the heterobranch gastropod superfamily Pyramidelloidea. The shells of the six study species consisted of thick crossed-lamellar (CL) layers that were sandwiched between thin outer and inner prismatic layers. Interspecific differences were observed in the number and thickness of the CL layers, the dip angle of the second-order lamellae of each CL layer, and the microstructure of the outer and inner prismatic layers. Of these, the microstructure of the prismatic layers may be useful as taxonomic characters distinguishing the genera and species of Pyramidelloidea. The distributions of observed character states were, however, inconsistent with conventional familial and subfamilial classification, supporting previous anatomical and molecular studies that have challenged the monophyly of pyramidelloid higher taxa.

Fossils of Divalucina soyoae Habe, 1952 and Cardilia semisulcata (Lamarck, 1819) have been recovered from a shallow-water assemblage of the upper Pliocene Seguchi Formation in Nagano Prefecture. The fossils mark the second oldest record of Divalucina soyoae and the oldest one of Cardilia semisulcata. The oldest fossil record of both species are from the Japan Sea side of Japan, not from the Pacific. Although both species live now in warm waters around Japan, Divalucina soyoae has not been found in the Japan Sea today. Moreover, the Pliocene occurrence of D. soyoae indicates a shallower habitat than it occupies today.

This is a list of the new molluscan taxa described by the late Iwao Hamatani from 1952 to 2017 with a bibliography as complete as possible. The bibliography consists of 59 scientific papers, 20 books, a book review, 35 popular articles, and four miscellaneous articles. Some articles were published by the high school biology clubs he worked with and not being available to the public, but they can be read at the Natural History Museum in Kishiwada City.