In the volume of the Palæontographical Society for 1883, I conclude the series of supplements to my work on British fossil Brachiopoda. Additional supplements will, no doubt, be called for every now and then. As our rocks continue to be searched, new forms will turn up, and specimens will be procured that will enable palæontologists to complete the history and illustration of a certain number of those I have been compelled to leave insufficiently made out, described and illustrated.