THE SIMIAD^. 461 



the other Lemurs (and indeed from that of all the other 

 Primates), and resembles that of the Rodents. 



Thus there is only one pair of incisors in each jaw,* and 

 these grow from persistent pulps and have a thick layer of 

 enamel on their anterior faces, whence they wear to sharp 

 chisel edges, like the incisors of the Bodentia. No canines 

 are developed, and there are four grinders with simple 

 cvowaas on each side above and below. 



2'2 1 1 



The formula of the milk dentition is d.i. -— d.c. — d.vi. 



2-2 0— n 



2-2 



The LemuridoE are confined to Eastern Asia, Madagascar, 

 and South Africa ; Madagascar presenting the greatest 

 number and diversity of genera and species. 



h. In the great group of the Simiadce, which contains the 

 AjDes and Monkeys, the attitude is sometimes habitually 

 quadrupedal, the axis of the body being horizontal ; but, 

 in a few species, the trunk is habitually held in a more in- 

 clined position, and the animals readily assume the erect 

 attitude. 



The Simiadce are sometimes terrestrial in habit, and 

 good runners, but they are always excellent climbers, and, 

 in some cases, they are necessitated by their organi- 

 zation to be almost as thoroughly arboreal as the Sloths. 



The hallux is always much shorter than the second digit 

 of the foot, and capable of very free movement in adduction 

 and abduction. 



The series of the teeth, in each jaw, is interrapted by a 

 diastema in front of the canine in the upper jaw, and 

 behind it, in the lower ; and the canine teeth are longer 

 than the others, the points of their crovms projecting for 

 a greater or less distance beyond the rest. 



In the skull, the length of the basi-cranial axis equals 

 more than haK the extreme length of the ca%'ity which 

 contains the brain. The absolute capacity of the cranium 



IF 



^ * Among tlie Lemvridce, the outer and upper incisors of JVi/cticsbtis 

 and Tarsius soon fall out. Lichanotus and Tarsius have only one pair 

 of incisors in the mandible. 



