The paper on the development and succession of the teeth in the armadillos, published in the Zoological Society’s _Proceedings_ in 1868, is, on the other hand, of considerable interest on account of its confirming the fact first mentioned by the French zoologist, Professor Paul Gervais, but generally overlooked by subsequent writers up to that time, that the common nine-banded armadillo (_Tatusia peba_) differs from its relatives in replacing some of its teeth by vertical successors. This at the time was an unexpected feature in any member of the so-called Edentate mammals; and tended further to break down the supposed hard and fast distinction between monophyodonts and diphyodonts. Closely connected with the subject of dentition is a paper on “The Affinities and Probable Habits of the Extinct Marsupial, _Thylacoleo carnifex_ (Owen),” communicated by Flower to the Geological Society of London in 1868, and published in the _Quarterly Journal_ of that body for the same year. After alluding to the paper on marsupial dentition, Professor Ray Lankester, in his obituary notice of Sir William in _Nature_, of 13th July 1899, observes of the communication under consideration that—“The next most striking discovery which we owe to Flower seems to me to be the complete and convincing demonstration that the extinct marsupial, called _Thylacoleo carnifex_ by Owen, was not a carnivore, but a gnawing herbivorous creature like the marsupial rats and the wombat—a demonstration which has been brought home to the eye even of the unlearned by the complete restoration of the skull of _Thylacoleo_ in the Natural History Museum by Dr. Henry Woodward.” If we are to believe later authorities, Flower’s demonstration of the herbivorous nature of the creature in question was by no means so “complete and convincing” as the learned Professor would have us believe; but of this anon.