416 



Their bodies are extremely broad in proportion to their length or antero-posterior diameter. 

 The articular bed for the head and tubercle of the first dorsal rib is contributed to, in equal 

 shares, by the last cervical and first dorsal vertebrae. Ten vertebrae show the impression of 

 the articulation of the head of the rib in addition to the first dorsal, and the neurapophyses 

 of these eleven dorsal vertebrae are directly perforated by the spinal nerves. The articulation 

 for the last rib is as equally divided between the two contiguous vertebrae as is that of the 

 first rib. The prominence supporting the articular surface for the head of the rib answers to 

 the 'parapophysis,' just as the prominence supporting the articulation for the tubercle of the 

 rib, represents the ' diapophysis.' The prominence in the first lumbar vertebra which arti- 

 culates with the under part of the anapophysis of the last dorsal, repeats, or tallies with, the 

 prominence in that dorsal which articulates with the head of the last rib : it is, therefore, a 

 ' parapophysis.' The diapophysis projects, as in the dorsal vertebrae, from the upper and outer 

 part of the base of the short and thick anapophysis, and this anapophysis presents, as in other 

 Armadillos, two articular surfaces : one, above, for the under part of the metapophysis ; an- 

 other, below, for the upper part of the parapophysis. Thus, the vertebrae are interlocked by 

 tenon-and-mortice joints, as Cuvier has described ; but it is by distinct parts of the vertebrae 

 from those which form the corresponding joints in the back bone of serpents. 



This and the following parts of the same skeleton were 

 presented by Charles Darwin, Esq., F.R.S. 



2298. The pelvis of the same Armadillo. 



The sacrum includes 12 vertebrae, the spines of which unite to form a continuous bony 

 crest. The anterior tuberosities of the ilia and the posterior tuberosities of the ischia are 

 distinct epiphyses in this young specimen : the former are supported by the metapophyses 

 of the first sacral vertebra, which also developes laterally two articular parapophyses. Ossi- 

 fication has not so far advanced as to unite the pubic bones together at the symphysis. The 

 posterior sacral vertebrae present the same remarkable breadth which characterizes the other 

 species of the genus Dasypus. 



2299. The manubrium sterni of the same Armadillo, with the first pair of dorsal ribs 

 and the ossified cartilages of the two succeeding pairs. These haemapophysial 

 portions of the costal arches are much longer than those of the first rib. 



2300. The left humerus of the same Armadillo : it is short, thick, strongly curved, 

 with prominent deltoid and supinator ridges, and is perforated above the inner 

 condyle. 



2301. The left ulna of the same Armadillo. 



2302. The left radius of the same Armadillo. 



