The Neotropical eumenine wasp Pachodynerus nasidens is recorded from Japan for the first time. Its recognition characteristics are noted. New records of this species from Micronesia and Polynesis are given and its distribution throughout the western Pacific is mapped and briefly discussed.
A new species of isometopine plant bug, Isometopidea gryllocephala, is described from Ishigaki Island in the Ryukyus, Japan. This is the third species of Isometopidea and has the northernmost distribution in the genus.
The type specimens of Aphaenogaster forms described by Wheeler from Japan were re-examined. A. verecunda Wheeler, 1928 is newly synonymised with A. japonica Forel, 1911 stat. nov., and A. famelica frontosa Wheeler, 1928, A. f. ruida Wheeler, 1928, and A. vapida Wheeler, 1928 are newly synonymised with A. famelica (Fr. Smith, 1874).
A small collection of Pycnogonida from shallow waters of Ogasawara (Bonin) Islands contains two species. One of them, Achelia curticauda, is new to science and is described, illustrated, and compared with similar species. This is the first record of pycnogonids from Ogasawara Islands.
The phylogenetic relationships of Platycephalidae and its related taxa were analyzed. Platycephaloidei and Scorpaenoidei form a monophyletic group supported by two synapomorphies : presence of a backwardly-directed opercular spine and an extrinsic muscle derived from the hypaxial. Platycephaloidei and Plectrogenium, the triglids and peristediids are monophyletic, characterized by a posterior pelvic fossa. Bembradium and Plectrogenium constitute a monophyletic group, which divided initially from remainder of the clade. Next Parabembras, followed by Bembras, branched off the latter. Platycephalidae and its sister group, including the triglids, peristediids and hoplichthyids, have 4 synapomorphies. The triglids, peristediids and hoplichthyids share 15 apomorphies. The peristediids and hoplichthyids constitute a monophyletic group supported by 8 synapomorphies. The newly-defined suborder Platycephaloidei includes the following 7 families : Plectrogeniidae, Parabembridae, Bembridae, Triglidae, Peristediidae, Hoplichthyidae and Platycephalidae. Platycephalidae is redefined, being a monophyletic group supported by 6 synapomorphies, and including 2 subfamilies and 17 genera, 3 of them new.