SIMIA. 19 



apart ; but these conditioDs cannot be regarded as the chief 

 cause of separated temporal ridges in Orang skulls, and, 

 moreover, in the skull 3oo they do not exist, and yet the 

 ridges are far apart. 



In the old male Spp, in its general features also resembling 

 the skull 3a, the fronto-parietal ridges remain far apart, even 

 although the animal is aged. The area, however, between 

 the ridges is covered with deep indentations — an abnormal con- 

 dition which may havei contributed to the non-union of the 

 ridges. 



The male skeletons also exhibit almost quite as much 

 variation in the length of their long bones as is manifested 

 by the skulls, in the particulars already indicated. One is so 

 remarkable for the shortness of its limb bones that Mr. Blyth 

 at first regarded it as a new species which he designated 

 S. curtus, but afterwards, when he had reviewed all the materials 

 at his disposal, he sunk the name in his catalogue as a synonymy 

 of S. satyrus. 



The skull 2>pp is remarkable for the number of depres- 

 sions on its frontal, as well as on its parietal, region. They 

 apparently resemble those described by Professor Humphry' as 

 occurring in an Orang from Borneo in the Anatomical Museum 

 of the University of Cambridge. There is a remarkable de- 

 gree of similarity between the two skulls, and they further 

 resemble each other in having the temporal ridges apart and 

 in possessing supernumerary molars. 



The depressions in this skull are chiefly confined to the 

 interspace between the ridges, but they occur without any 

 symmetry. There is one large depression on the parietal, 

 immediately behind the left superciliary ridge 0'''70 long and 

 O'-fiS broad, with another still deeper depression behind it, 

 C'SO long and C'TS broad. A little removed from the right 

 superciliary ridge is a long partially-interrupted depression 

 l*-55 long and 0' "50 broad, which may be regarded as the 

 equivalent on this side of the depression just described, and 

 from which it is separated by a prominent eminence. All of 

 these depressions occur on the frontal, but immediately behind 

 them there is another depression occupying the mesial line 

 of the skull, on the beginning of the parietal, C'SO broad and 



' Joum. Anat. and Phys., Vol. VIII, 1874, p. 136. PI. VII, figures 4, 5 and 6. 

 The specimen described by Professor Humphry is stated to have been a 

 female, but the figure in which the canines are represented as large would 

 seem to indicate, along with the general characters of the skull, that the 

 animal had been a male. 



