PRIMA TES 



68 1 



tin 1 clavicles are well developed; and the radius and ulna are never 

 united. The scaphoid and lunar of the carpus, and commonly also 

 the centrale, remain distinct from one another. There are usually 

 five digits furnished with well-developed nails in both the manus 

 and the pes ; but the pollex may be rudimentary or wanting. The 

 hallux, except in Man, is opposable to the other digits, and has a 

 flat nail (absent in Simia) ; and the pollex, 

 when present, is usually also more or less 

 opposable. The terminal phalanges of 

 the digits are flattened (except in the 

 second digit of the pes of the Lemu- 

 roidea), and not cleft at their extremities. 

 The fingers and toes generally do not 

 taper towards their extremities, but (ex- 

 cept in Chi nun us) are dilated, flattened, 

 and rounded at their tips. The humerus 

 has no entepicondylar foramen, nor the 

 femur a third trochanter. In the ali- 

 mentary canal (Fig. 324) the stomach is 

 generally simple, although sacculated in 

 the subfamily Semnopithecince of the 

 Cercopithecidce ; and there is always a 

 caecum, which is generally of large size. 

 The placenta may be either non-deciduous, 

 or discoidal and deciduous. There are 

 always two mammas in the pectoral 

 region, except in Chiromys ; and the 

 testes descend into a scrotum. 



The Lemuroidea are decidedly low in '"t^tine being omitted, a, duo- 



, r i r x- a i • i ilenum ; i, ileum ; cm, cwcum ; r, 



the scale of organisation, their placenta- rec . tum . 

 tion being of a lower type than that 



of the Insectivora; and all the Primates retain generalised features 

 in their pentadactylate limbs and more or less bunodont cheek-teeth. 

 In respect to cerebral characters and other features the higher 

 representatives of the order have, however, acquired a specialisation 

 clearly indicating their right to occupy the highest position in the 

 animal kingdom. So far as the available material admits of forming 

 an opinion, fossil forms appear to indicate an intimate connection 

 between the Lemuroidea and Insectivora, so that in some cases it is 

 almost impossible to determine whether an extinct type should be 

 referred to the former or to the latter group. It is noteworthy 

 that while in all existing Primates the upper molars are of a quadri- 

 tuberculate type, in the extinct Lemuroid genus Anaptomorphus 

 they are trituberculate. 



Fig. 324. — Alimentary canal of 

 Gaiago, the greater part of the small 



