92 



of that animal in the possession of j\Ir. Cross, Mr. Owen regarded 

 aa being that of a malė individual from its size and from the deve- 

 lopment of the cranial ridges. 



The sexual peculiarities observable in the cranium of both the 

 Bomean and Sumatran Pongos are well marked, and are exemplified, 

 first in a diiFerence of relative size, that of the female being about 

 ith smaller ; secondly, in a much smaller development of the cranial 

 ridges ; and thirdly, in the symphysis menti being of less depth, the 

 cranium of the female approaching in these respects, according to 

 the usual law of sexual development, towards the characters of the 

 immature animal. The smaller of the crania of the two Bomean 

 Orangs, Mr. Owen regarded as indicative of a species of Simia, Erxl., 

 eąually distinct from the great Pongo of Borneo (Simia JVurmbii, 

 Fischer, Sjmopsis Mammalium, p. 32, No. 43), and from the Ordng 

 of Sumatra (Simia Abelii, Fischer, ibid. p. 10, No. 2*); and whUst 

 regretting that his conclusion as to the specific distinction of the 

 smaller Orang, (which, cceteris paribus , mušt be at least one third less 

 than either of the two preceding Orangs) necessarily reposed on a 

 comparison of the cranium alone, he at the šame time observed that, 

 as the cranium in ąuestion was in every respect entire, and with 

 the series of teeth complete, it served to establish that deduction on 

 the sound basis of dental and osteological characters. 



Mr. Owen therefore proposed to designate the lesser Orang of 

 Borneo, Simia Morio, and proceeded to describe the cranium as fol- 

 Iows : 



" The size and form of the cranium of the Simia Morio at first 

 suggests the idea of its being an intermediate stage of gro\vth be- 

 tween the young and adult Simia Satyrus, or Pongo; but this is dis- 

 proved by comparison of the teeth of S. Morio, with the permanent 

 teeth in the adult Pongo, and Avith the deciduous ones in the 

 young Simia Satyrus, as •vvell as with the gerras of the permanent 

 teeth concealed in the jaws of the latter. For TV^hile the teeth of 

 S. Morio are much larger than the deciduous teeth of the young 

 S. Satyrus, tliey have difFerent relative sizes one to another from those 

 which are observed in the permanent teeth of the full-grown: the 

 molares and bicuspides of the S. Morio being smaller, the canini much 

 smaller, while the upper incisores have nearly, and the lower in- 

 cisores fully, the šame dimensions as those of the great Pongo. 



" The teeth in the jaws of a ąuadrumanous cranium maj'^ be known 

 to belong to the permanent series, by the absence of the/orfl?«/«ff, 

 which, in an immature ci-anium, are situated behind the deciduous 

 teeth, and \vhich lead to the cavities containing the cro\vns of the 

 permanent teeth. Tliis character is very conspicuous on comparing 

 the cranium of Simia Morio •vvith that of a young Simia Satyt-us, in 

 which the deciduous series are present, together ^dth the first per- 

 manent molares. The deciduous teeth in the young Orang, besides 

 their smaller size, are more or lessprotruded from their sockets. and 

 thrust apart from one another by the vis a tergo of their huge suc- 

 cessors, -vvhile the teeth of S. Morio are lodged firmly in the jaws ; 

 and, with the exception of the characteristic interval between the 



