362 PROF. W. H. FLOWER ON THE EDENTATA. __[Apr. 18, 
prehension and mastication of food, they are quite as near, if not 
nearer, to the Anteaters. They may truly be regarded as intercalary 
types, bridging over the gulf which now exists between them. The 
teeth are certainly those of the Sloths, even to the actual number in 
most genera; but the diminution of that number in Celodon leads to- 
wards their total suppressionin Myrmecophaga. In the lengthening 
of the anterior part of the skull in Megatherium, but wore strongly 
marked in Scelidotherium, the commencement of the Myrmecophaga 
type is clearly seen; and that they had tongues longer and more 
protractile than those of existing Sloths (perhaps even prehensile, as 
Professor Owen suggests) is very probable. The vertebral column, 
ribs, sternum, and tai! were far more Myrmecophagine than Brady- 
podine. In the scapula they possess a character which is shared 
by both Sloths and Anteaters but by no other mammal. The 
coracoid bone and the coracoid border of the scapula join over the 
coraco-scapular notch, converting it into a foramen. The recent 
discovery of clavicles in a rudimentary state in all three species of 
Myrmecophaga’* adds another common character to the group, though 
perhaps not one of first-class importance. It must, however, be 
noted that in no species of Manis has any trace of a clavicle been 
found. The flattening of the femur, and development of a linear 
ridge along its external border, is common and peculiar to the Sloths, 
Anteaters, and Megatheres. The special characters of the manus in 
these three families are all derivations from a common type; but in 
this portion of their organization the Megatherioids show their rela- 
tionship with the Anteaters much more than with the Sloths. In the 
mode of setting the foot to the ground, and in the absence of claws 
upon one or more of the outer digits, the likeness is most surprising. 
The manus of the Pangolins, on the other hand, although presenting 
some superficial resemblances, is formed on a different type, in most 
respects more conformable to that which is normal among mammals ; 
but it has the peculiarity (which it shares with all known Carnivora) 
of connate scaphoid and lunar bones, and in the deep median clefts 
of the ungual phalanges it resembles Perameles among the Mar- 
supials. 
Passing from this brief review of the osteological characters, we 
find in the arrangements of the arterial system of the limbs a close 
resemblance between the Sloths and Anteaters ; and though the tail 
is so reduced in the former, its caudal artery is surrounded by a 
well-developed plexus, such as we could hardly account for, except 
upon the supposition that it were a remnant of a condition in which 
the tail resembles that of the Anteaters or Megatheres. In Manis, 
no reéia mirabilia appear to be developed in connection with the 
arteries of the limbs—although one has been found, in at least one 
species, in the tail; but it is also present in animals as far removed 
as the Spider Monkeys. 
A part of the organization to which it is natural to attach much 
importance in tracing affinities is that concerned in the reproductive 
function. The organs of both male and female Sloths and Ant- 
' See W. A. Forbes, P. Z.8. 1882, p. 287. 
