44 
Through the reduction of the coracoids in all flightless birds, there is an interval 
between their sternal articulations: this is long and concave in the Dodo, but is 
longest and most deeply concave in Apteryx ; it is long but almost straight in Rhea ; in 
Casuarius and Rromaius it is narrow but deeply notched ; in Struthio it developes a short 
episternal process. In no Grallatorial sternum with both ecto- and ento-lateral pro- 
cesses (as e.g. Otis, (Edicnemus, Charadrius) do the former project, as in Didus and the 
Easores, immediately behind the costal margin, but they are continued, parallel with 
the keel, from the outer and posterior angle of the sternum, distant from the costal 
margin. In old Plovers the entolateral process joins the contiguous angle of the sternal 
body, and converts the inner notch into a foramen. 
In the breast-bone of the Dodo we plainly discern the Columbine modiflcation of the 
Gallinaceous type, simplifled in the minor development of those parts relating adaptively 
to the power of flight, and expanded and excavated for the support of the larger gizzard 
with its heavier grindstones^ 
In comparing the pelvis of Bidunculus and Goura (PI. XII. flg. 5) with that of I)idus 
(PI. VII. flg. 1), the correspondences are: — in the general shape, proportions and dis- 
position of the ilia ; in the articulation therewith of the last pair of moveable ribs, and 
of the short straight confluent pleurapophyses of the three succeeding sacral vertebrse ; 
then follow, as in Didus, three vertebrae without pleurapophyses, these reappearing in 
the next two with their extremities converging to abut against a prominence of the inner 
surface of the ilium in the same relative position. The difference here is in the two 
equal and more slender rib-buttresses, in place of the single stronger one, which is the 
more common structure in Didus ; but in Goura I have noted an instance in which it 
agreed with the Didunculus on the left side, and with Didus on the right, in the last- 
specified character. In the Crown-pigeons, also, there is an indication of the transverse 
ridge marking off the under part of the centrum of the first sacral from the rest, and those 
that follow are less expanded than in the Dodlets ; moreover in Didunculus they show 
a median canal instead of a ridge, while the ridge is feebly indicated here and there and 
there is no canal in Goura. In neither Didunculus nor Goura do the sacral centrums 
behind the last rib-abutments diminish in breadth so suddenly as in Didus : in both the 
winged Pigeons the hinder part of the pelvic cavity is relatively deeper and narrower 
than in Didus; in both, also, the upper and anterior concave tracks of the ilia are deeper; 
and in Didunculus the mesial borders do not attain the neural crest, but leave a pair of 
open longitudinal canals at that part of the pelvis ; in Goura those margins reach the 
neural crest, but do not overtop it at any part. In Goura the acetabula are more in 
advance of a median position than in Didunculus, Columha magnifica, or Didus. Although 
the ischiadic foramina are completed by terminal confluence of the ilium and ischium in 
> The habit of the Dodo to avail itself of extraneous crushers to a galUnaoeous or struthious degree, is attested 
by the quotation, p. 8, not the least interesting of the fruits of the extensive research of the learned and con- 
scientious author of the Article Dodo, in the ‘ Penny Cyclopaedia.’ 
