The late Admiral Spratt, R.N., and Dr. John Murray, of the “Challenger” Expedition, have, in their brochures on Maltese Geology, made allusion en passant to the occurrence of chert nodules in the Globigerina limestones of the Maltese islands. Neither of these gentlemen, however, gave any details of the nature, mode of occurrence, or distribution of the concretions, an omission which was probably due to the restricted area of the horizon at which the nodules are found, and to the irregular and sparse manner in which thev are distributed.