XIV. 1 Shufeldt: Osteology of Porphyrio 95 
A coracoid in our present subject is a stout, straight bone, 
much expanded for its sternal moiety, which part is concave 
posteriorly and nearly flat anteriorly. As in Fulica and Galli- 
nula it develops a sharp process at the outer inferior angle of 
its shaft, and the two bones in none of these genera meet in 
the coracoidal groove of the sternum in the articulated skeleton. 
All three bones of the* arch assist in forming, superiorly, the 
“tendinal foramen.” The very delicately formed “fourchette” 
is a U-shaped bone in all of these paludicoline birds (Plate III, 
fig. 11), and lacks anything like a hypocleidium. At the median 
point of the arch below, however, there is usually developed a 
minute process on the upper side, directed upward. 
None of the bones of the pectoral arch in any of these genera 
is pneumatic, which is also true of the sternum; in fact there 
is little or no pneumaticity of any part of the skeleton, as we 
find it among the various genera of the marsh birds. Indeed, 
this is what we would expect in the case of fowls that make 
so little use of such powers of flight as they possess. 
There is no mistaking the sternum of any species of this in- 
teresting group, and the characters of the bone are much the 
same throughout. The anterior border of the keel in Porphyrio 
slopes away posteriorly, more than it does in Gallinula and the 
coots ; but beyond this the differences are barely of generic rank 
(Plate III, fig. 11). 
The sternal body is narrow and much concaved on its dorsal 
aspect. Markedly prominent, the quadrilateral “costal proces- 
ses” are flaring and truncated superiorly. A very small manu- 
brium is present, and the costal grooves are practically con- 
tinuous with a median notch above them on the superior border. 
The “carina” is well developed, being concave on its anterior 
border and convex on its inferior, the “carinal angle” being 
acute. There are six articular facets upon either costal border 
in Porphyrio and Fulica, but apparently only four or five in 
the Gallinula from the Seychelles Islands. 
The midxiphoidal process, with the carina running the entire 
length of it on its ventral aspect, is bluntly pointed posteriorly, 
and an isosceles triangle in outline, the somewhat blunt angle 
being acute. 
This xiphoidal portion of the bone is profoundly one-notched 
upon either side; the notch being triangular, with the angle 
pointing anteriorly. This gives rise to a long, lateral xiphoidal 
process on either side ; each process is narrow, of uniform 
width, and somewhat expanded at its free extremity. Plate II, 
fig. 7, gives some idea of the ossifications that take place in 
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