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depressions and foramina, their sternum receiving air exclusively from the intercostal 
fosse, whilst these in Dinornis are imperforate (Pl. LX XIII. fig. 2, 0 0 0). 
The anterior border of the sternum of D. rheides (P). LXXIV. fig. 4) is straight, no 
part projecting forward as “ manubrium” or receding; it is slightly and equably curved 
transversely toward the chest (as shown at, a, fig. 4); it is strongly bent from without 
inward, or from below upward, where it terminates by a narrow subobtuse margin, over- 
hanging, in the vertical position of the bone, the pneumatic depressions and the general 
concavity of the inner surface. This margin is continued on into each costal process 
(figs. 3 & 4, d d), which extends upward and outward in the same slight transverse curve 
for rather more than an inch beyond the costal border, with an antero-posterior thick- 
ness, at the middle, of 9 lines, and with an obtuse and apparently slightly expanded 
termination, which, however, is not quite entire in the specimen. 
The coracoid depressions (fig. 4,4) are feebly defined by a transverse concavity 
occupying the fore part of the costal process, not extending mesially much beyond the 
line of the outer or lower border of the costal tract (fig. 4,¢¢). This tract (Pl. LAXMI. 
fig, 2) shows ridges for the articulation of two sternal ribs, the anterior one (jm) being 
bituberculate, as in the Ostrich; the posterior and shorter ridge (7) is simple: three 
intercostal fosse (0 00) are defined by these ridges; the anterior and largest has a 
somewhat irregular surface, the two following are smoothly concave. 
The sternum, which is 1 inch across the first fossa, contracts to a thickness of 4 lines 
at the end of the third fossa. The length of the costal tract is 2} inches. The outer 
border of the lateral process (4) continues obtuse but decreasing in thickness to about 
one-third from the lower end, where it becomes a ridge: the inner border is a sharper 
ridge through the whole extent. The length of each lateral process is 6 inches, the 
average breadth 6 lines, being very little more at its commencement. 
The length of the sternum in a straight line along the middle is 9 inches: the lateral 
processes (hh) extend about an inch beyond the middle one (gy); this, halfway from 
its commencement, measures 2 inches across, 
The breadth of the sternum at the ends of the lateral notches (ff), or origins of the 
lateral processes, is 5 inches 6 lines; the breadth of its fore part, including the costal 
processes (d d), in a straight line is 7 inches. 
The middle of the entire part of the sternum is reduced to the thinness of cartridge- 
paper; it gains a little in thickness at the median process; but this thins off again to 
the end. 
The outer surface is marked by fine lines, indicative of aponeurotic insertions; the 
inner surface is for the most part smooth and polished. 
Longitudinally both median and lateral processes have a slight outward or downward 
flexure, giving a gentle sigmoid contour to the bone in that direction, as in fig. 2, 
Pl. LXXIIL. 
The second sternum of Dinornis rheides in the collection examined at Mr. Sumpter’s 

