In many respects, the discovery of the Pithecanthropus erectus appears to be one of the most important since the Neanderthal skull was brought to light in 1857, and hence the main facts concerning it deserve early notice in this Journal. This memoir contains a full description, with illustrations, of part of a skull, a molar tooth, and a femur, found in the later Tertiary strata of Java, and pertaining to a large anthropoid ape, which is believed to represent a new genus and family interme...