20 SHUFELDT — OSTEOLOGY OF THE CUCKOOS. [Jan. 4, 



ones, when a gradual contraction takes place as we pass into the 

 dorsal region. But even here the segments are comparatively 

 broader in their transverse diameters than we often find them. 



In the fifth vertebra the neural spine is placed further forward 

 on the bone, but is very small ; it is absent in the sixth, or only 

 faintly indicated, and it does not appear in the series again until 

 we find it as a pronounced crest on the fifteenth segment. Some- 

 times, however, a low, tuberous elevation marks its site in the few 

 ultimate cervicals. 



Prezygapophyses in the fifth vertebra stand almost directly out- 

 ward, while the postzygapophyses very prominently point to the 

 rear. Little modification takes place in the former of these pro- 

 cesses as we examine the succeeding vertebrae, their general direc- 

 tion remaining about the same, but the articular facets they bear 

 face more and more toward the median plane as we proceed back- 

 ward. With the postzygapophyses, however, the case is otherwise, 

 for as we descend the cervical series we find these become gradually 

 shorftr and stouter with a wider divergence, while their facets, from 

 facing downward and outward, come to look almost directly down- 

 ward. 



We find strongly marked metapophyses surmounting the bases of 

 the postzygapophyses in the sixth to the ninth cervical vertebrae in- 

 clusive ; after that they disappear, and are but feebly reproduced in 

 the dorsals, where they occur on the superior aspects of the ends of 

 the transverse processes. 



On the fifth cervical vertebra the lateral canar is at its forward 

 part, appropriating about the anterior moiety of the entire centrum. 

 Its outer wall may show a slight perforation, while the parapophyses 

 which project from it behind are on either side a short and needle- 

 like spine. As we pass down the series this perforation becomes 

 larger and larger, until in the tenth vertebra it has broken through 

 the hinder free margin of the lateral canal and disappeared, leaving 

 in the segment only a shorter passage and a deep concave notch 

 indicating its site. Pari passu with this change, the parapophyses 

 and pleurapophyses pass through the usual evolution in that direc- 

 tion, to result in the perfect and free pair of ribs found in the 

 thirteenth vertebra. Faint beginnings of a carotid canal are also 

 seen in the fifth vertebra, in the presence of a shallow excavation 

 at the anterior end of the under side of the segment. This be- 

 comes better and better marked to include the tenth vertebra, 



