DR. GUNTHER ON THE ANATOMY OE HATTERIA. 
607 
twice as long as the preceding one, terminating in a short terminal cartilaginous or 
semiossified hfemapophysis ; in the middle of its length , on its posterior edge , it is [like all 
the following ribs) provided with an apophysis directed obliquely backwards and upwards , 
overlapping the following rib, of the same form as, and homologous with, the processus 
uncinatus of birds. The first of these apophyses is fibro-cartilaginous ; the two or three 
following are semiossified, the following entirely osseous, and the posterior, again, less 
ossified than the middle. None of them are completely anchylosed to the rib, but 
attached to it by a short suture strengthened by ligaments*. When we consider the 
transition from the dilated heemapophysis of the sixth and seventh vertebras to the com- 
pletely ossified uncinate (epipleural) process of one of the middle dorsal vertebrae, we 
shall be inclined to regard these uncinate processes as parts of the hasmapophyses, sepa- 
rate and removed from the distal end of the pleurapophyses in proportion as the latter 
increase in lengthf. 
All the complete ribs, fourteen in number, have a broad, compressed head, joined to 
a low oblique ridge of the centrum of the vertebrae; they are entirely smooth, without any 
tubercle in their arched basal region, which has a shallow longitudinal groove in front ; 
they are slender, becoming gradually a little broader towards their distal extremity. 
The anterior are but little, the posterior considerably, shorter than the middle, the length 
of which is nearly equal to the extent of five dorsal vertebrae. The haemapophyses of all 
(the last two excepted) are divided into two semiossified pieces united by a joint (fig. 24) ; 
the upper (a), thinner and shorter piece (of about one-fourth or one-fifth the length of 
the rib) follows the direction of the rib, whilst the lower is directed inwards and forwards. 
The haemapophyses of the first three ribs reach the sternum, the two foremost not 
showing any peculiarity of form, and the third approaching the succeeding in form by 
having a slight expansion in front and behind. The lower pieces of the haemapophyses 
of all the following ribs are much dilated and imbricate (fig. 24, b, and fig. 20), each with 
a rounded wing-like expansion in front and behind ; they have the form of a trapezoid 
situated obliquely on each side of the medial line of the abdomen ; its upper anterior angle 
is one of the expansions overlapping the preceding haemapophysis ; the upper posterior 
angle is produced to meet the’ costal piece of the haemapophysis; the lower posterior 
angle is the other expansion overlapped by the produced lower anterior angle of the 
succeeding haemapophysis ; and this latter angle reaches one of the bones of the abdo- 
minal sternum. The haemapophysis of the two hindmost ribs consists of one long bent 
semiossified cartilage only, and the expansions are less developed than in the other ribs. 
* In young pheasants, just on the point of being hatched, I have found the uncinate processes of the ante- 
rior and posterior ribs cartilaginous, ossification having commenced only in those of the middle ribs, at some 
distance from the rib ; the body of the ribs was completely ossified ; of course, no anchylosis of the processes to 
the bone had taken place. The same I found to be the case ‘in a Talegalla of the same age, a bird which is 
capable of flying almost as soon as it leaves the egg-shell. 
t I am confirmed in this view by a comparison of the same parts of the Crocodile, where a similar process is 
developed near the distal end of the ribs ; in young individuals this process is still confluent with the haemapo- 
physis, as in the fourth rib of Eatteria. 
