Mr. J. C. VAN DER MEER MOHR, Zoologist at the Deli-Station at Medan (Sumatra), has in 1926 and in August and December 1927 collected at Pulau Berhala 37 species and one variety of Decapod Crustacea and a variety of Gonodactylus chiragra (Fabr.); these species are described in this paper. As far as I am aware, the carcinological fauna of this islet was still entirely unknown. The collection contains a new species of the genus Litocheira Kinahan, besides a new variety of Gonodactylus chiragra among the others that are in the main common indo-pacific forms, two well-preserved males of the rare Grapsus gracilipes H. M.-Edw. and one fine specimen of Alpheus splendidus Cout., also a rare species, should especially be mentioned. Furthermore this paper contains interesting remarks about a species of Pinnotheres from the shells of Arca granosa, collected at Indramajoe (Java), and, finally, detailed descriptions of Litoch. integra (Miers) and Litoch. subintegra Lanch., species which were still imperfectly known. Besides the species here described, also Menaethius monoceros (Latr.) and Panulirus versicolor (Latr.) are found at Pulau Berhala.