224 ' MR. W. K. PARKER ON THE OSTEOLOGY 
a small, distinct rib-head ; in front of that, the small pleurapophyses are all welded to 
their vertebree (c.) ; none of them are very long, the longest being at the middle of the 
neck, The ‘‘ proccelian” facet of the atlas is only a half-moon, whilst in the Rhea 
small styles nearly enclose the odontoid process. The cervical vertebre, generally, are 
merely like an enfeeblement of the neck-bones of the Great Ostriches. The carotid 
canals are as imperfect as in Fowls, Pigeons, and their congeners; and the relative 
length and thickness of each bone is much like what is seen in ordinary members of 
those types, and also in the Ostriches themselves. The fusion of the last cervical with 
those of the dorsals (c.d.) shows the introduction of some leaven or other ; this is cer- 
tainly not a struthious character: and yet we, regal vertebrates, cannot tell whence that 
zymotic influence comes, nor whither it goes. The ribs are scarcely longer than the 
hemapophyses ; they are moderately spongy: the second dorsal has a small appendage, 
and the next a trace, whereas in the Rhea the first four dorsal ribs have large appen- 
dages ; the corresponding four ribs in the Apteryx have them very large. The Tinamou 
comes nearest the Emu in this respect, whilst the Ostrich is intermediate between the 
Rhea and the Emu. I only find eighteen sacral vertebre (Pl. XX XIX. fig. 3, sm., & 
Pl. XLI. sm.), whereas the Emu has twenty-two, as may be seen in the young bird’. 
In the Rhea the middle of the sacrum is abortively developed, and only the embryo 
would give us the number. The Tinamou’s sacral vertebra are not so stout as those 
of the Fowl, but they are much like them, the width of the pelvis allowing a much freer 
development of the transverse processes and stunted ribs than in any of the large 
Ostriches. Indeed the sacrum, together with the hinder part of the ilium on each side 
(Pl. XLI. fig. 3, il. sm.), gives us a gently convex, smooth surface, more Pigeon-like than 
even in the Curassow itself, and the spaces between the sacral diapophyses are merely 
indicated on the upper surface by two symmetrical rows of small foramina. Between 
the anterior parts of the ilia, however, the spaces are larger, and there is something of 
the feebleness of the pelvis of the Syrrhaptes (Pl. XLI. fig. 5) in that part. The caudal 
vertebra have been shorn of their strength; the spinous and transverse processes are 
very short and feeble, and there is the slightest attempt at inferior processes (Pls. XX XIX. 
& XLI. cd.). They are six in number, and the last is evidently three in one ; only four 
mere centra project beyond the ischium in the Rhea, but I find nine in the chick of the 
Emu ; indeed the number is very variable in the ‘‘ Struthionide.’”’ The two or three 
fused and compressed bones at the end of the Tinamou’s coccyx must be contrasted 
with the ten fused coccygeal bones of the Common Duck. The ralline compression of 
the pelvis, caused by an almost vertical position of the ossa innominata, has been lost in 
this aberrant little Ostrich. 
The shape of the iliac bone (i.) is very much like that of the Tree-Partridge and the 
Curassow, not only in the anterior, but also in the posterior moieties ; it is nearest 
* The extraordinary ornithic fore-and-aft growth of the pelvis is the cause why so many vertebre should be 
thus married together, bones which are quite free in the Reptilia. 
