The main taxonomic characters of two genera, Pseudomicrocentria Miller, 1970 and Ummeliata Strand, 1942, are summarised. Two new species, Pseudomicrocentria uncata, from Sabah, East Malaysia andUmmeliata jambi, from Sumatra, Indonesia, are described. Pseudomicrocentria uncata, newspecies, described only based on male specimens, resembles P. simplex Locket, 1982 from Singapore. Ummeliata jambi, newspecies, is particularly similar to the East Palearctic-Oriental U. insecticeps (Bösenberg & Strand, 1906). Each new species differs from its congeners by structural details of the genitalia. In addition, Ummeliata insecticeps is reported from India and Laos for the first time.

Two new species of Paramanota (Diptera: Mycetophilidae: Manotinae), Paramanota rodzayi, new species, and P. trilobata, new species, are described from Brunei and Thailand, respectively. The new species, P. rodzayi, represents the first record of this genus from the island of Borneo. The barcode mitochondrial cytochrome oxidase subunit I (COI) sequence, partial 12S ribosomal RNA and partial nuclear 28S ribosomal RNA sequences of P. rodzayi are also provided, indicating its possible relationship to P. orientalis Tuomikoski, 1966.

Quidnipagus palatum and Tellinides timorensis have not been previously recorded from Singapore in the literature (e.g., Morris & Purchon, 1981; S. K. Tan & Woo, 2010), and are herein reported for the first time. Nevertheless both species are probably not very rare and the lack of reports may be due to a general lack of sampling efforts and reports on the local malacofauna.