It is useful from time to time to take stock of our knowledge in connection with such a geological problem as that of the fauna of the Bokkeveld Beds, so that we may ascertain to what stage in the process of its elucidation we have arrived, and may note the direction in which the evidence is pointing. An indication of the principal gaps in our knowledge may also be obtained in this manner, and new suggestions as to the more promising lines of investigation. The conclusions arrived at from such a survey may be employed tentatively as working hypotheses, but it may be premature to base upon them confident generalisations. Approaching the question of the composition, relations, origin, and distribution of the Bokkeveld fauna in this spirit of caution and with the foregoing objects in view, we find firstly that a considerable advance has been made in our knowledge of it and allied faunas during the last few years. The researches of Ulrich, Kayser, Clarke, Katzer, Thomas, and others in South America have given us an immense amount of fresh information on the Devonian faunas of that continent, and the South African fossils themselves have been studied by Lake, Schwarz, and the author. Their general poor state of preservation is a matter of regret, but the increase in the material available has cleared away some of the difficulties met with by Salter and other previous workers. Much undoubtedly remains to be learnt from work in the field, and we may expect further yields of new species from different localities in the immense area still to be explored.