(1) "Un oiseau auroit des côtes plus larges, et munies chacune d'une apophyse récurrente[C]; son metatarse n'auroit formé qu'un seul os, et n'auroit pas été composé d'autanut d'os qu'il a de doigts." These, though they may not be characters which are those of birds, are certainly not eminently reptilian. The elongated form of the tarsals in birds is peculiar, but quite functional, as may be seen among the Penguins, where, when the so-called tarso-metatarsal bone is no longer erect, it becomes much shorter, and is nearly separated into three distinct bones. The cretaceous Pterodactyles appear to have this bone exactly like that of birds. [Footnote C: This shown in other specimens since figured, and in the specimen from Stonesfield in the Oxford Museum.] (2) "Son aile n'auroit eu que trois divisions après l'avantbras, et non pas cinq comme celle-ce." This is a difference, but a difference of detail only, and not a reptilian character. The creatures have wings; and no reptile known, from recent or fossil specimens, has wings. The general plan of the wing, though very unlike, approximates to that of a bird. Most birds have two phalanges in the long finger, though some have three. One Pterodactyle is described as having only two phalanges in the wing-finger, while most of the German specimens appear to have four phalanges. In birds the longest finger appears to be the middle one, while in Pterodactyles it is the innermost one. (3) "Son bassin auroit eu une toute autre étendue et sa queue osseuse un toute autre forme; elle seroit élargie, et non pas grêle et conique." The pelvis of Pterodactyle is not reptilian, and no living reptile has a pelvis like it. It is not unlike the pelvis of a Monotreme, but the ilium is more Avian. It resembles the pelvis of Dicynodon. And the discovery of a long-tailed bird-like the Archæopteryx shows that the tail is like that of old birds, even if it also presents some analogy in form to that of certain reptiles and mammals. (4) "Il n'y auroit pas eu de dents au bec; les dents des _harles_ ne tiennent qu'à l'enveloppe cornée, et non à la charpente osseuse." This is not a reptilian character. Among reptiles some tribes have teeth, others want them; and among mammals some animals are without teeth, though they are so characteristic of the class. It is an anomaly that birds should all be toothless. And so, without citing the supposed teeth of _Archæopteryx_, it may be affirmed that it would be no more remarkable for some birds to have teeth than it is for some mammals and reptiles to be without them.