iv.] EDENTATA. 47 



and irregular and comparatively rudimentary transverse 

 processes. 



In Hyperoodon, the whole of the cervical vertebrae are 

 ankylosed together. In the other Ziphioids several of the 

 posterior vertebrae are free, and the allied Cachalot, or Sperm 

 Whale (Physeter), presents a condition not met with in any 

 other known Cetacean : the atlas is free, and all the other 

 neck vertebrae are completely united. 



Among the various members of the order EDENTATA, the 

 cervical vertebrae present very different conditions. 



In the Armadillos (Dasypodidcz) the bodies are extremely 

 short, broad, and depressed, and several are commonly anky- 

 losed together ; the corresponding neural arches being also 

 .united, the neural, and to a certain extent the vertebrarterial, 

 canals form continuous tubes. The orifices for the spinal 

 nerves perforate the united pedicles. The atlas is always 

 free. The vertebras that are united are the second and third, 

 or the second, third, and fourth (Tatusia peba), and in some 

 species the fifth also. The spinous processes of the axis and 

 those of the fused vertebrae in general are very large, but the 

 neural arches of the hinder free vertebrae are extremely 

 narrow, and the spinous processes rudimentary. The trans- 

 verse process of the seventh has an inferior lamella, nearly 

 as large as that of the sixth, and is not perforated. 



In Orycteropus, the Pangolins (Manis), and the Anteaters 

 (Myrmecophagd^ the neck vertebrae are more normal in form, 

 and are not ankylosed. In the last-named genus, the verte- 

 brarterial canal of several (2, 3, 4, in M. jiibald] of the 

 vertebras perforates the pedicle obliquely, and enters the 

 neural canal posteriorly, much as in the Camels. 



Among the leaf-eating Edentates, or Sloths, the neck 

 vertebras present some remarkable peculiarities, especially as 

 to number. 



