306 Annat.s of the Carnegie Museum. 



are free ; while in tlie dorsal region the 19th, 20th, 2Tst and 22d are 

 solidly fused together so as to form a single bone. The 23d vertebra 

 is again free, after which the succeeding 14 are coossified together to 

 form the jjelvic sacrum. Finally we find 6 free caudals in the skeleton 

 of the tail, plus a terminal pygosfvic, which last is comparatively very 

 small for the size of the bird, being somewhat elongated, pointed and 

 shaped like a blunt lance-head. It is a process projecting forwards from 

 its antero-inferior angle. 



The at/as has the usual ornithic-type form, with its cup for the 

 occipital condyle profoundly and roundly notched above, while its in- 

 ferior spine is conspicuous, rather elongated, and is extended directly 

 backwards. Passing this vertebra, the first thing that commands our 

 attention in the cervical system of bones is their unusual slenderness, 

 and their progressive elongation from the axis vertebra to include the 

 1 2th of the chain^the 9th to the 12th inclusive having almost exactly 

 the same length, or about 5.3 cm. After the 12th they gradually 

 shorten and widen again, until they come to assume the form of verte- 

 bra seen in the dorsal region. Through these elongated vertebra; the 

 neural canal is also small, and even does not exhibit much increase of 

 calibre where the neural cord gives off the brachial plexus. With the 

 exception of the caudal vertebrae the entire chain of bones seems to 

 be more or less pneumatic, the atlas, perhaps, being the least so of all, 

 and the consolidated piece of the back the most so. 



The axis vertebra has a long, low, thickened neural spine with 

 broadly rounded superior edge ; its hicmal spine is likewise reduced 

 to an elongated low crest with its inferior border somewhat sharpened. 

 The odontoid process is prominent, pointed and somewhat tipped up 

 in the direction of the neural canal. A long, extremely low, sharp 

 and thin neural crest, longitudinally disposed, is also found upon the 

 third vertebra, and upon all its successors to include the twelfth. It 

 suddenly shortens up and becomes slightly more manifest in the 13th — 

 distinctly so in the 14th and 15th — while in the i6th it is the most 

 conspicuous feature of the bone, short, lofty and markedly bifurcated 

 behind. This is pretty much the case, too, in the 17th and iSth seg- 

 ments, while in the coossified dorsal piece the neural crest is for the most 

 part low and inclined to be spreading, especially anteriorly. In the 

 free 23d it is much shortened, high, and considerably thickened. On 

 the extreme forepart of the third vertebra there is a short meciian hcemal 

 spine, that in the case of the 4th vertebra becomes distinctly bifid, 



