XXI 
ON A NEW SPECIES OF MACRAUCHENIA 
(M. BOLIVIENSIS) 
Quarterly Journal of the Geological Society of London, vol. xvii, 1861, 
Dp. 73—84. (Read November 21, 1860.) 
THE vertebrate remains obtained by David Forbes, Esq., F.R.S., 
F.G.S., from the mines at Corocoro, under the circumstances detailed 
in his paper “On the Geology of Bolivia and Southern Peru,” con- 
sist of the following parts of the skeleton of apparently one and the 
same Mammal :—1. A portion of the right maxilla and palate, with 
fragments of grinding teeth. 2. Rather more than the right half 
of the occipital portion of the skull. 3. A middle cervical vertebra, 
nearly entire. 4. A fragment of a posterior lumbar vertebra. 5. A 
small portion of a right scapula, 6. A crushed fragment of the 
proximal end of an ulna. 7. Part of the proximal end of the left 
tibia. 8. The entire left astragalus, and part of the right astragalus. 
The bones are all in the same, and that a very peculiar, mineral 
condition—the Haversian canals being for the most part filled up 
with threads of native copper; so that the fossils are not only 
exceedingly dense, but, in consequence of their internal flexible 
metallic support, their thinner and more delicate parts bend, rather 
than break, when force is applied to them. 
The characters of the cervical vertebra and of the astragalus, which 
are fortunately the best-preserved of all the fossils, at once demon- 
strated the remains to belong to the genus Macrauchenia (Owen), 
while the entire absence of epiphysial sutures in the vertebra and 
the long bones, and of similar indications of immaturity in the 
fragment of the skull, proved the animal to have attained its adult 
condition. The vertebra and the astragalus, however, have not 
more than half the size of the corresponding bones of the species, 
DD2 
