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 Cmlodon leads to- 

 wards their total suppression in Myrmecophaga. In the lengthening 

 of the anterior part of the skull in Mec/af.herium, but more strongly 

 marked in Sceliclotherium, 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 preliensile, as 

 Professor Owen suggests) is very probable. The vertebral column, 

 ribs, sternum, and tail 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 iu 

 these three families are all derivations from a common type ; but iu 

 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 retia mirahilia 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.S.1882, p. 287. 



