Page:Quarterly Journal of the Geological Society of London, vol. 31.djvu/842

686 to be amply sufficient to identify the species to which it belonged. In order to render the distinction more immediately evident between this specimen and the corresponding vertebra of the common English Fox, and at the same time to show how exactly it resembles the same bone in the Arctic Fox, I have subjoined figures of the three bones, in which it will be seen that, besides their considerable difference in size from the larger, the two smaller vertebras correspond with each other in all other respects.

The chief points of difference between the axis vertebra of the Arctic and of the common Fox may be briefly stated to consist in:—

(a) The smaller size of the former.

(b) The slenderness and more abrupt divergence of the transverse processes.

(c) The much greater prominence of the median keel or carina on the under surface of the centrum.

(d) A difference, difficult to describe, but sufficiently obvious on comparison, in the form of the anterior articular facets.