In _Didunculus_ the pubis coalesces with the ischium behind the small obturator foramen, but leaves a second or posterior elongate ischio-pubic vacuity. The greatest amount of resemblances with the pelvis of the Dodo is found in that of different members of the Dove-tribe. In comparing the pelvis of the Dodo with that of the Vulture (Pl. XII. fig. 6), we find in the latter that the first two confluent sacral vertebræ; supporting moveable ribs are succeeded by several with short abutting ribs, the extent of this part of the sacrum being nearly one-half of the whole, instead of one-fourth as in _Didus_ and the Doves. The reappearance of rib-abutments after four ribless sacrals is in the posterior third of the sacrum, and they are continued to the end of that bone from the last four vertebræ of the series, constituting a very marked difference, both as to number and the character of the vertebræ in the sacral part of the pelvis. With regard to the iliac bones, the anterior concave track occupies two-thirds of the extent of the bone in _Vultur_, not one-half as in _Didus_ and most Doves; the breadth of the posterior parts of the ilia with the intervening sacrum in the Vulture is relatively less than in the winged Doves, and differs in a greater degree from that characteristic part in the sacrum of _Didus_. In _Ciconia_ the antacetabular part of the pelvis is relatively longer, and the iliac bones are more expanded anteriorly. In _Platalea_ the proportions are more nearly those in _Didus_. In _Otis_ the ilia touch the fore part of the sacro-spinal ridge, but leave both posterior and anterior apertures of the ilio-neural canals widely open. In _Œdicnemus_ and _Charadrius_ they are grooves, the ilia not reaching the sacral spines. The external concavity of the ilium is longer, narrower, and deeper, in most waders, than in _Didus_. In _Eudyptes_ and _Aptenodytes_ the ilia are more expanded anteriorly, but the whole pelvis is narrower and longer than in _Didus_. The Gar-fowl (_Alca impennis_)[35], _Uria_, _Podiceps_, and _Colymbus_, all show still longer and narrower proportions of the pelvis.