288 THE ANATOMY OF VERTEBRATED ANIMALS. 



Immense submaxillary glands extend back over the thorax, 

 and cover the tongue with a viscid secretion, when it is thrust- 

 in to the nests of the ants, upon w^hich the Myrmecophaga 

 preys. The insects, entangled by thousands in this substitute 

 for birdlime, are then dragged back into the mouth of the 

 Ant-eater, and swallowed. The pyloric portion of the stomach 

 is so exceedingly thick and muscular as to be comparable to 

 a gizzard. The brain presents numerous convolutions, and 

 has a large corpus callosum. The anterior commissure is also 

 remarkably large. In the female, the uterus is simple, but has 

 a double os uteri. The placenta is said to be discoidal in 

 form in 3IyrmeGophaga didactyla. 



b. The group of the Squainata contains the single genu? 

 3fcmis, species of w^hich are found both in Africa and Southern 

 Asia. In these singular animals, the body is covered wdth 

 overlapping, horny scales, and they have the powder of rolling 

 up like hedgehogs. In walking, the long claws of the fore- 

 foot are bent under, so that their dorsal surfaces rest upon the 

 ground, while the weight of the hinder part of the body is 

 thrown upon the flat soles of the hind-feet. 



The skull is elongated, the premaxilla is small, and the 

 zygoma usually incomplete. The pterygoids are much elon- 

 gated and extend backward beyond the bullate tympanic 

 bones, but they do not unite in the middle line. The mandible 

 has no ascending ramus, and its condyle is flat. Air-passages 

 in the walls of the skull place one tympanum in communication 

 with the other and extend into the squamosal bone. There 

 are no clavicles. The " xiphoid " extremity of the sternum is 

 large, and may be produced into two long cornua, as in Lizards. 

 The mouth is toothless. 



The large salivary glands extend on to the thorax. The 

 stomach is divided into a thin- walled cardiac sac, lined by a 

 dense epithelium, and a thick muscular pyloric portion. It 

 is always found to contain numerous stones. The placenta 

 appears to be difi'use and non-deciduate. 



c. The Tuhididentata are also represented only b}^ a single 

 genus, Orycteropus^ which is a native of South Africa. The 

 body is hairy, provided with thoracic and inguinal teats, and 

 the ears are long, not short or rudimentary, as in the preceding 

 genera. In both the fore- and the hind-limbs, the foot rests 

 evenly upon the ground and m-ainly upon the plantar surfaces 

 of the strong claws. The fore-foot has only four digits, in 

 consequence of the absence of the pollex, while the hind-foot 

 is pentadactyle. 



