The present authors independently from one another studied oological material from Java. The results of their studies are combined in the present paper. Hellebrekers deals with three collections, held by the Rijksmuseum van Natuurlijke Historie at Leiden, brought together (a) by M. E. G. Bartels and his sons (4770 shells), (b) by J. G. Kooiman (280 shells), and (c) by H. J. V. Sody (175 shells). Of these collections those made by Bartels and Sody consist almost exclusively of eggs from West Java, while that made by Kooiman originates from East Java. Hoogerwerf gives details of 1020 shells of his own collection, almost all of which originate from West Java. These were obtained after the appearance in 1949 of a paper in which he published the colour descriptions and measurements of 5680 Javanese eggs which, however, were not weighed (Hoogerwerf, 1949). In the present paper the weights of 2200 of these previously discussed shells are published by Hoogerwerf. The remainder of the 1949 material (including the Bouma collection from Central Java) is in the Zoological Museum at Bogor, Indonesia, and therefore could not be weighed for the present study. In total, below are published the measurements of 6245 and the weights of 8240 shells. A large number of eggs of the families Phalacrocoracidae, Ardeidae, Ciconiidae, Threskiornithidae and Plataleidae of which Hoogerwerf gives details here, were not collected, but put back into the nests after being measured, as this was done also with part of the material reported by him in 1949. In Hoogerwerf's part it often happens that the number of measured shells is not in accordance with that of the weighed ones. This is caused by the fact that weights of previously examined shells — of which the measurements are not included in the present paper — are added; also the measurements