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

 connexion of the vertebrce assists materially in enabling the head 

 to overcome the resistance of the dense fluid through which they 

 perpetually move, so in the animals of this genus a like advantage 

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

 denser material in which they excavate their retreats. The bodies 

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

 transverse bars, the bony sheath of the spinal marrow 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 larger 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 j but the 

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

 1st, 2nd, and 3rd dorsal vertebrce are the longest, and slope consi- 

 derably backwards; the rest of the spines, together with those of 

 the lumbar vertebra, also incline in the same 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 must have been 

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

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

 not accompanied by any corresponding inflections of the spine, the 

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

 pressed as in the quadrupeds which move by bounds. Hence there is 

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

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

 rection towards the sacrum. The relation which 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 faculties 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 upwards, outwards and forwards, and like strutts or braces, 

 assist in supporting the tegumentary mass which covers the body, 

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

 nerves pass out by foramina proper to each individual vertebra, and 

 not in the interval of two. 



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

 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, measuring 1 inch in length and 7| 



