124 LLOYDS NATURAL HISTORY. 



ponderous Gorilla and the genus H07710. In external characters 

 the Monkeys and Apes have in general a shorter and less Dog- 

 like nose than the Lemurs, thin lips and a more distinct face ; 

 while their eyes, situated on the face, are invariably directed 

 forwards, and never outwards, or to the side. The opening of 

 their nostrils is either outward (as in those inhabiting the New 

 World), or downwards (as in the bulk of the Old World 

 species). All of them are covered with hair ; the tail may be 

 long, short, or wanting. The proportions of the fore-limbs 

 to the hind- vary much in the different groups. The great 

 toe, as well as the thumb, is (except in a few species) fully 

 opposable, so that in the majority of members of the Sub- 

 order, the foot is as good a prehensile organ as the hand. 

 From this circumstance comes the designation, Q2cadrujna7ia, 

 or •' four-handed," so often applied to these animals. In a few 

 species the thumb is rudimentary or absent, but the fore- 

 finger, the absence of which characterised some of the Lemurs, 

 is always present and well developed, and the corresponding 

 digit in the foot (except in the Marmosets) has a flat nail 

 instead of a claw. The mamm?e of the A?ithropoidea are 

 always situated on the breast. If we examine the structures 

 underlying the skin, we find that in the skull the orbits are 

 entirely shut in by a bony wall, so that the finger cannot be 

 passed into the temporal depression behind, as could be done 

 in the Lemurine skull, and that the lachrymal foramen opens 

 within the cavity for the eye. In the present Sub-order there 

 is no toothless space in the mid-line of the upper jaw, the 

 incisor teeth being set close together ; but there is always a 

 vacuity, except in Man, between the incisors and the canine 

 tooth. The lower canine teeth do not resemble in form the 

 incisors, nor do they protrude horizontally, as in the Lemurs. 



