190 EDENTATA 
of Argentina, described as Promegatherium and Promylodon, are 
respectively distinguished from Jegatherium and \ylodon by 
the presence of bands of enamel on the teeth, which points 
to the descent of the Edentates from mammals with enamelled 
teeth. 
The Tertiary North American forms described as l/oropus and 
Morotherium,! and originally regarded as Edentates, would appear to 
be aberrant Ungulates. 
Family MYRMECOPHAGID. 
Externally clothed with hair. No teeth. Head elongated. 
Mouth tubular, with a small terminal aperture, through which the 
long, vermiform tongue, covered with the viscid secretion of the 
enormous submaxillary glands, is rapidly protruded in feeding, and 
withdrawn again with the adhering particles of aliment, which are 
then sucked into the pharynx. Clavicles rudimentary. In the 
manus, the third toe is greatly developed, and has a long falcate 
claw; the others are reduced or suppressed. The pes has four or 
five subequal digits with claws. Posterior dorsal and lumbar 
vertebr, with additional interlocking zygapophyses. Tail long, 
sometimes prehensile. Uterus simple. Placenta dome-like or 
discoidal. Brain fairly convoluted, and with a large corpus cal- 
losum and anterior commissure. The animals of this family are 
the “Anteaters” par evrcellence. They feed exclusively on animal 
substances, mostly insects. One species is terrestrial, the others 
arboreal ; none burrow in the ground. They are all inhabitants of 
the Neotropical region. 
The reproductive organs, as noticed on p. 181, are of the 
same general type as in the Bradypodide. 
Myrmecophaqu.n—Skall greatly elongated and narrow, its upper 
surface smooth and cylindriform. Anteriorly the face is produced 
into a long, tubular rostrum, rounded above and flattened below, 
with terminal nares, and composed of the mesethmoid ossified 
for more than half its length, the vomer, the maxillez, and the long 
and narrow nasal bones, the premaxille being extremely short and 
confined to the margin of the anterior nares. The zygomatic arch 
is incomplete, the styliform jugal only articulating with the maxilla 
in front, and not reaching to the very short zygomatic process of 
the squamosal. The lachrymal foramen is in front of the margin of 
the orbit. There are no postorbital processes to the frontals, i any 
other demarcation hetween the orbits and the temporal fosse. Palate 
extremely elongated, and produced backwards as far as the level of 
1 See E. D. Cape, licr. Naturalist, vol. xxiii. p. 152 (1889, 
* Linn. Syst. Vat, 12th ed. vol. i. p. 51 (1766) 
