140 PLEISTOCENE MAMMALTA. 
Hyena, are points by which the first phalanges of those animals may be separated from 
those of Felis spelea. We know of no others that can be confounded with them. 
§ 2 B. Second Phalanges.—The second phalanges of all the Feles are characterised 
by their triangular section, and by the outward projection of their distal articulation ; the 
latter allows the claw phalange when retracted to fall back outside the axis of the bone, so as 
to raise the point of the claw over the articulation, and thus protect it from injury. Those 
of Felis spelea (Pl. XXI, 11, 12, 18, 14) closely resemble their homologues of the 
hind limb, but are longer and more bent externally. The proximal articulation (a), 
which, following the section of the shaft, is triangular, is composed of two slight concavities 
divided by a median ridge; it is deeply excavated on the palmar ridge by a notch and 
pit, in which is inserted the tendon of the flexor sublimis muscle. On its dorsal edge is 
a small flattened tuberosity (4), forming the apex of the triangle for the attachment of the 
tendon of the extensor communis. ‘The bone tapers gradually down to the distal end of 
the shaft. The distal end is a somewhat rectangular mass, of nearly double the width of 
the shaft and projecting outwards (d) from the axis of the shaft, and giving the whole bone 
a curved outline. The articulation closely resembles that on the first phalange of the 
thumb, which performs similar functions. It affords a means of differentiating the digits 
of the same paw, that of the second phalange of the second digit forming an obtuse angle 
with the inner edge of the bone, that belonging to the third a nearly right angle, that 
belonging to the fourth being slightly acute, while that belonging to the fifth is more 
acute and very much shorter in its transverse diameter. Like the first phalanges these 
bones are much longer and more slender than those of the hind paw. 
We have been unable to detect any difference of form between the phalanges of Lion, 
Tiger, and Felis spelea. We have met with no British specimens of the third phalanges 
sufficiently perfect to describe, with the exception of Pl. V, fig. 14: they only differ from 
each other in size, those of the fore being in the main larger than those of the hind paw. 
§ 2 y. Measurements.—The following table of measurements shows that the supe- 
riority of size observable in the other bones of Felis spelea as compared with those of Tiger 
and Lion is carried out in every bone of the fore paw. 
