PROFESSOR HUXLEY ON THE OSTEOLOGY OP THE GENUS GLYPTODON. 43 
lumbar vertebrae respectively were anchylosed together, with only an imperfect mobi- 
lity at the junction of the two solid masses, I do not see how, in any important respect, 
his view of the matter differs from mine. 
The last criticism which Professor Burmeister offers, refers to what he terms my error 
in ascribing five toes to the fore foot, when, as he affirms, it possesses only four. Pro- 
fessor Burmeister states that I have figured five toes to the foot of the Glyptodon in the 
lecture already referred to ; but he is mistaken ; only four toes are there represented, 
numbered, according to the digits of the typical foot which they represent, 2, 3, 4, 5. 
In the ‘ Proceedings’ (p. 325) I have expressly stated — 
“The trapezium possesses only a very small double articular facet on its palmar face. 
If this gave support to a metacarpal, it must have been very small ; and as at present 
neither it nor any of the hallucal phalanges have been discovered, it is possible the 
pollex may have been altogether rudimentary. In any case the pollex must have 
been so much smaller and more slender in proportion than that of Dasypus, that the 
animal must have had a practically tetradactyle fore foot.” 
The errors, therefore, to which Professor Burmeister adverts, appear to me to arise 
to a great extent from his not having rightly comprehended my statements ; and in part, 
it may be, from our having to deal with different objects. 
Part II. — Description of the Skeleton of Glyptodon clavipes, Owen ( Hoplophorus Selloi, 
Lund 1). 
The materials which have been available for the following description of the osteology 
of Glyptodon are, in the first place, the skeleton referred to in the previous section 
as having been presented by Senor Terrero to the Royal College of Surgeons; 
secondly, the detached parts which have been already described by Professor Owen, and 
are now contained in the Museum of the Royal College of Surgeons ; thirdly, some 
fragmentary specimens in the British Museum ; and fourthly, photographs of a skeleton 
of Glyptodon in the Museum of Turin. The two latter sources of information, however, 
are of altogether secondary importance, and will be adduced merely in confirmation of 
the results obtained from the study of the two former series of materials, — in treating 
of which, I shall speak of the fragments of Glyptodon clavipes described by Professor 
Owen as the “ type specimen,” and of the skeleton presented by Senor Terrero as the 
“ new specimen.” 
§ 1. Description of the Skull of Glyptodon clavipes. 
In the new specimen * the anterior part of the skull, from a line drawn transversely, 
immediately behind the zygomatic processes, to the anterior end of the snout, is in a 
remarkably good state of preservation — the boundaries of the anterior nares, the antero- 
lateral parts of the maxillary bones, the nasal, and the fore part of the frontal, bones 
being quite uninjured. Behind the imaginary transverse line in question this cranium 
* Plate IY, figs. 1 & 3, Plate V., and Plate YI. figs. 1, 2 , 4 , & 5. 
