Taxonomy of the New World bee genus Agapostemon Guérin-Méneville – new names and synonymies (Hymenoptera: Halictidae)
Cory S. SHEFFIELD et al.
1-23, Published on 25 May 2021, art. 751 (1)
The pseudodichotomous Dasya sylviae sp. nov. (Delesseriaceae, Ceramiales) from 60–90 m mesophotic reefs off Bermuda
Craig W. SCHNEIDER et al.
24-37, Published on 27 May 2021, art. 751 (2)
A morphological and molecular review of the genus Goniurosaurus, including an identification key
Hai Ngoc NGO et al.
38-67, Published on 31 May 2021, art. 751 (3) 
One new genus and nineteen new species of ground spiders (Araneae: Gnaphosidae) from Iran, with other taxonomic considerations
Alireza ZAMANI et al.
68-114, Published on 04 June 2021, art. 751 (4) 
Monsters in the dark: systematics and biogeography of the stygobitic genus Godzillius (Crustacea: Remipedia) from the Lucayan Archipelago
Lauren BALLOU et al.
115-139, Published on 07 June 2021, art. 751 (5) 
Three new genera and five new species of the tribe Meconematini (Orthoptera: Tettigoniidae: Meconematinae ) from Southwestern China
Yan-Lin CHANG et al.
140-158, Published on 08 June 2021, art. 751 (6) 
Review of the millipede genus Levizonus Attems, 1898, with description of a new species from the Far East of Russia (Diplopoda, Polydesmida, Xystodesmidae)
