135 



as is vvell known, in the Cetacea ; and as in that order this firm 

 connexion of the vertebrce assists niaterially in enabling the head 

 to oveicome the resistance of the dense fluid through vvhich they 

 perpetually movė, so in the animals of this genus a likę advantage 

 may be derived ftom this structure during the act of displacing the 

 denser materiai in which they excavate their retreats. The bodies 

 of the 4th, 5th, 6th, and 7th cervical vertebrce are in the form of 

 transverse bars, the bony sheath of the spinal marrovv being of 

 equal thickness at every part, resembling in that respect the cer- 

 vical vertebrce of the Mole, Talpa Europcea, Linn. ; they have, 

 however, the transverse processes much iarger than in that animal. 

 In Das. Peba the 5th, 6th, and 7th cervical vertebrce have distinct 

 spines, but these are deficient in the present specimen. 



•' Cuvier assigns twelve as the number of the dorsal vertebrce in 

 the Encoubert, but there were not more than eleven in this spe- 

 cimen, as clearly appears from the number of the ribs, all of which 

 have been carefully preserved : and indeed, the costal vertebrce are 

 readily distinguishable from the lumbar by a well marked articular 

 process on each side of the body, for the head of the rib ; but the 

 lašt cervical also participates in this character. The spines of the 

 Ist, 2nd, and 3rd dorspJ vertebrce are the longest, and slope consi- 

 derabiy backwards; the ręst of the spines, together with those of 

 the lumbar vertebra, also incline in the šame direction, but in a less 

 degree. 



" Every one who has seen the living Armadillo running about 

 the open plot of ground in the Society's Gardens mušt have been 

 struck with the machine-like manner in vvhich the body is carried 

 along. The short legs are almost concealed, and their motions are 

 not accompanied b}' any corresponding inflections of the spine, the 

 two extremities of the trunk not being alternately raised and de- 

 pressed as in the qnadrupeds vvhich movė by bounds. Hence there is 

 no centre of motion in the vertebral column, or point tovvards 

 which the spinous processes converge, but all these have a di- 

 rection tovvards the sacrum. The relation vvhich the structure of 

 the vertebral column bears to the mode of progression of a qua- 

 druped is extremely interesting, and enables us to judge in some 

 degree from the spine alone of the locomotive facuUies of a fossil 

 species. 



" There is another peculiarity to be noticed in the spine of Da- 

 sypus, viz. the elongated form of the anterior articular processes, 

 especially of the hinder dorsal and of the lumbar vertebrce : these 

 project upvvards, outvvards and forvvards, and likę strutts or braces, 

 assist in supporting the tegumentary mass vvhich covers the body, 

 and vvhich may be not unaptly compared to a tiled roof. The spinal 

 nerves pass out hy Jhramina proper to eachindividual vertebra, and 

 not in the interval of tvvo. 



" The ribs are on each side eleven in number, and six of these Ure 

 true. The sternal portions are completely ossified, as in Birds, and 

 joined to the dorsal portions by a distinct articulation, The first pair 

 are short, and remarkably broad, mcasuving I inch in length and /i 



