302 Dr. H. Burmeister on Glyptodon and its Allies. 
verrucosus ; and these scales belong, in my opinion, to the same 
animal, to which therefore this name may be applied. 
The pelvis in question, which I regard as belonging to this 
G. verrucosus, is well figured in Robin’s ‘ Journal d’Anatomie et 
de Physiologie’ for March 1866, pl. 2, where M. Pouchet de- 
scribes it as belonging to a new species, G. giganteus, founded 
by M. Serres in a paper which I do not know. This well- 
executed figure gives a good idea of the strength of the pelvis 
and the great size of the animal. As the very well-preserved tip 
of the tail in our public Museum is 2 feet 8 inches long and 7 
inches in diam. at its commencement, we may calculate that the 
animal was 10-12 feet in length, if not more, and that its body 
was an enormous mass, like a large oval rock. Nevertheless 
this species was not the largest of the family—the tail of G. tu- 
berculatus, figured in the ‘ Ostéographie,’ pl. 1. fig. 4, and pre- 
served in our Museum, being of double the size, comparing its 
general figure with that of the former. From the precise similarity 
in the position of the elliptical and radially striated figures on 
the two tails, I was at first inclined to believe that both belonged 
to the same species; but as I have now seen three other speci- 
mens of both tails of the same form, I must regard them as be- 
longing to different species. To understand their difference in 
general size, it is sufficient to compare the smallest lateral ellip- 
tical figure, like a rosette, on the tails of the three species. In G. 
clavipes this rosette measures 21 inches, in G. verrucosus 44 ches, 
and in G. tuberculatus 52 inches. If this difference be truly 
indicative of the general size, as I believe to be the case, the 
last-mentioned species was one-fifth larger than that named G. 
giganteus by M. Serres. 
With regard to the general form of the tail, I will only repeat 
what I have already said in my first communication—namely, 
that the tail of every true Glyptodon had rings, probably six in 
number, before the large cylindrical apex which alone was pre- 
viously known. This apex contains in its interior ten small ver- 
tebree ; and beyond the sacral vertebra the skeletons have always 
three or four free vertebra covered by the hinder part of the cara- 
pace. On comparing the size of the bodies of these vertebre 
with the first of the apex of the tail, it is evident that there was 
between them a series of from six to eight vertebrae which were 
covered by the free rings of the tail. In this way I calculate 
the total number of the caudal vertebree of G. clavipes at 20-23. 
As I am engaged upon extended descriptions of the species in 
the Museum, to be published in the second part of the ‘ Anales 
del Museo publico de Buenos Aires,’ which will soon be sent to 
press, I will not here enter upon any further details, but conclude 
this communication with a short revision of the species in question. 
