PHALANGISTID^. 255 



The skull of P. Taguanoide* differs from the skulls 

 of the species helonging to Belideus, in being smaller 

 in proportion to the bulk of the animal, in having the 

 zygomatic arches stronger and flattened at the sides, 

 in being deeply concave between the orbits, instead 

 of flat, and in having the palate deeply emarginated 

 behind it terminates, in, fact opposite the second 

 false molar, whereas in Belideus it terminates behind 

 the line of the posterior molars. The nasal bones 

 are much shorter, arid the strength of the skull and 

 lower jaw indicate a greater power in the muscles 

 connected with mastication. 



Section 2. Belideus. Dentition : Incisors, f ; 

 canines, i;J ; false molars, |;| ; true molars, |;|=40. 

 The anterior incisors of the upper jaw are large, 

 somewhat suddenly dilated immediately above their 

 insertion in the intermaxillaries, and assuming a 

 triangular form. In P. flaviventer they are broader 

 than in either P. sciureus or P. breviceps. The next 

 incisor on each side is smaller than the posterior one, 

 narrow at the base, and broad at the apex. The 

 third incisor is broad, and has a sharp incurved cut- 

 ting edge. The canine is tolerably large ; separated 

 by a small space on either side from the false molars 

 and the incisors, compressed and pointed, and its 

 anterior and posterior edges are sharp ; the apex 

 projects beyond the level of either of the molars. 

 The first molar on each side is rather large, broad, 

 compressed and pointed, has a very faint indication 

 of an anterior and posterior lobe, and two distinct 

 fangs, (which is not the case in the small and cyliu- 



