THE EDENTATA SQTJAMATA. 337 



numerous convolutions, and tas a large corpus callosxim. 

 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 Myrme- 

 cophaga didactyla. 



h. The group of the Squamata contains the single genus 

 Manis, species of which are found both in Africa and 

 Southern Asia,. In these singular animals, the body ia 

 covered with overlapping, horny scales, and they have the 

 power 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 fiat soles of the 

 hind feet. 



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

 zygoma usually incomplete. The pterygoids are much 

 elongated and extend backwards beyond the bullate tym- 

 panic 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 diffuse and non-deciduate. 



c. The Tubulidentata are also represented only by 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 nidimentary, as in the 

 preceding genera. In both the fore and the hind limbs, 

 the foot rests evenly upon the gi'ound and mainly upon the 

 plantar siu-faces 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. 



z 



