Abstract A new genus and two new species of potamiscine freshwater crabs (Potamidae) are described from the Abor Hills in the Upper Siang District of Arunachal Pradesh State, northeastern India. Abormon gen. nov. is morphologically most similar to Pararanguna Dai and Chen, 1985, from Yunnan Province in China but can be differentiated by the setose dorsal surface and the medially concave posterolateral margins of the carapace, the concave lateral margins of the male telson, the relatively low dorsal flap on the terminal segment of the male first gonopod, and the anteriorly open and transversely ovate vulvae. Abormon capillosum sp. nov. can be distinguished from A. praecalvum sp. nov. by characters of the carapace, pereiopods, male pleonal somite 6, male gonopods, and vulvae.

Abstract Here, we report the first occurrence of Trizocarcinus Rathbun, 1914 (Brachyura: Euryplacidae) from the South Atlantic (Brazil). Trizocarcinus tacitus Chace, 1940 was collected in the upper continental slope of the Potiguar Basin, northeastern Brazil. The new record expands by 3000 km the southern distribution of the species in the Western Atlantic.

Abstract In the present paper, a new species of Achaeus Leach, 1817, is described from Easter Island and dedicated to the memory of Michael Türkay. This record represents the first inachid spider crab and the sixth endemic brachyuran to be described from the island. It can be differentiated from congeners by its relatively short carapace, with the postorbital region not elongated, the arrangement and number of tubercles on the dorsal carapace surface, prominent hepatic lobe, presence of a large anterodistal lobe on the ocular peduncle, as well as structures of the third maxilliped and ambulatory legs.