SIMIA.. 21 



associated with separated temporal ridges and au abnormal 

 number of teeth, Orang skulls presenting any of these 

 characters, either singly or in association, should be carefully 

 observed. 



Supernumerary teeth occur on both the upper and lower 

 jaws of the left side. In the former the supernumerary tooth 

 is a small erect two-fanged cylindrical tooth with two cusps. 

 The normal last molar is deformed, consisting of three distinct 

 internal cusps, with a large external cusp equalling the con- 

 joint dimensions of the three former. In the skull described 

 by Professor Humphry the additional tooth occurred on each 

 side of the upper jaw, and, although smaller than the other 

 teeth, both were well formed and with the normal number of 

 fangs. 



The supernumerary tooth in the lower jaw is quite as large 

 as the last molar and has its crown directed forwards to the 

 right side, as in the Orang skull described by Professor Hum- 

 phry, due to the circumstance that it is set in the base of the 

 eoronoid process. From its position its crown could never 

 be brought into use, but the hinder margin of the eingulum 

 is partially worn awaj' by friction against the upper super- 

 numerary tooth. 



The female skull S/i has a well-formed additional molar 

 behind the normal last tooth on each side of the lower jaw, 

 each perfectly erect and in no way out of position. 



Among these adult male Bornean skulls there is consider- 

 able variation, not only in the breadth of the front upper 

 incisors, but in the length of the dental line from the pre- 

 molar to the last molar, and in the dimensions of the molars, 

 and in some skulls more particularly of the last molar,\ 



Throughout the series there is considerable diversity in 

 the extent and form of the nasal bones. In the skull Svv the 

 nasals are V-4!b long, expanding from C'SS to U''50, their 

 greatest width. In the skull Spp these bones show a decided 

 tendency to unite with the maxillaries, whereas in skull 3ss 

 the nasals are little, if at all, expanded below, and are l^'SO 

 long with a maximum width of 0"'35, exhibiting no. tendency 

 whatever to union either with the frontal or maxillaries. 

 In the skull 3tt the maxillaries form a broad suture between 

 the orbits, and the nasals disappear, being represented by 

 a small azygos bone 0"'55 in length and O^'IS in greatest 

 breadth, so that it is quite possible that occasionally in Orangs 

 the nasals may be suppressed or lost in the maxillaries, so 

 insignificant is their fragmentary representation in the skull. 



