92 Dr. Burmeister on the Species of Glyptodon 
by a description and a drawing in the second part of the work 
of Dr. Lund (tab. 35. fig. 1). 
The seventh vertebra is moveable and free, but maintains 
almost the same form as one of the four which are united with 
the axis.” It is a very small bone, transversely elongated, with a 
large, almost triquetral perforation in the centre, and three pro- 
cesses—the upper one short, and the other two strong ones at 
the sides. The lower portion, which in other Mammalia con- 
stitutes the rather thick body of the vertebra, is a very delicate 
plane, of scarcely any thickness in the centre, and half an inch 
in breadth. 
The vertebral column, or spine, appears to me to be the most 
remarkable part of the ‘animal, it being a solid arched canal, 
without division into separate vertebree in conformity with the 
rule in other mammals. This vertebral canal is bent, as the 
form of the animal requires, and is armed in its superior part 
with three crests, of which the middle corresponds to the spinous 
process [neural spine, Owen], and those of the sides to the 
transverse processes [or rather to the metapophyses, Owen] 
of each vertebra in other Mammalia. But of the body [cen- 
trum] of the vertebra, which in Mammalia is generally very 
thick, nothing is seen; and the lower part of the canal, which 
corresponds to the bodies of the vertebrze, is most fine and thin 
in all its circumference. The canal alters in shape a little: 
towards the fore part it is wide and low; and towards the 
back, little by little, narrower, but higher, and in this way the 
three crests meet. The whole of the vertebral canal is divided 
into three parts, of which the two anterior correspond to the 
dorsal vertebra, and the third to the lumbar vertebree. 
The first part of the canal is the smallest ; beneath, in the 
lower part, it is about 24 inches long, and 4 inches above. Its 
width in the middle is about 7 inches. It is composed of 
three united vertebree—the first small, nearly of the same 
size as the last cervical vertebra, and the other two larger, 
demonstrated by the holes in the sides, from which issue the 
nerves of the myelon. The upper surface is smooth, and exhi- 
bits a high and thick backward prolongation, which rises con- 
siderably at the sides of the bone. Here we see two other pro- 
longations, which correspond to the transverse processes of the 
three vertebre : the first is very strong, prolonged in an antero- 
posterior direction backwards, and corresponds to the first two 
vertebrae ; the second is very short and thin, but also broad. 
On these processes we see the articulations of the first three 
ribs—the first im the anterior part of the first prolongation, 
the second in the posterior part, and the third in the exterior 
part of the second prolongation. This first, trivertebral part is 
