276 PROFESSOR OWEN ON THE EXTERNAL CHARACTERS 
and limbs which he assigns to the ‘‘ tribe,’ may be added, as more important and 
distinctive, those of the skeleton, the brain, and the digestive organs. The most 
conspicuous of the osteological characters are the great relative breadth and flatness of 
the sternum, and the reduction of the caudal vertebre to a non-projecting ‘ os coccygis ; 
the feeble met- and an-apophyses in the lumbar vertebre contrast also with their inter- 
locking development in lower Catarrhines. In the digestive system the absence of 
cheek-pouches, and presence of an ‘ appendix vermiformis czeci,’ are characters of the 
Pithecina, Is. Geoffr. Their dental distinction is seen in the conformation of the grinding 
surface of the true molars, which in the lower jaw presents five low tubercles, two on 
the inner and three on the outer and back part, instead of their development in 
transverse pairs or ridges as in the lower Catarrhines. In the brain may be noticed 
the bipartition of the ‘corpus mammillare,’ and the absence of the ‘ trapezium’ on the 
medulla oblongata. 
Of the latisternal or broad breast-boned Apes (Pithecina), one section has ischial 
callosities, the other not. ‘To the first belong the Gibbons or ‘‘ Long-armed Apes” 
(‘ Arm-affe,’ Kuhl), Scleropyga, natibus callosis; to the second, the true Apes (‘ Affe,’ 
Kuhl)’, Dasypyga, natibus villosis. In the Dasypygal division the Orangs (genus 
Pithecus, Geoffr.) manifest, agreeably with their geographical position, the nearest 
affinities with the Scleropyga, in the length of the upper limbs and the proportionally 
small size of the hallux: the Chimpanzees (genus Troglodytes, Geoffr.) show the higher 
position in the proportions of the upper limbs to the trunk, the large size of the hallux, 
and other characters set forth in the present and former memoirs on the Anthropoid or 
Dasypygal Apes. 
The Gorilla is shown, by its osteology, to appertain to the latisternal section of 
ecaudate Catarrhines’ ; and therein, by the absence of ischial callosities (‘‘ natibus tectis”’), 
to the Dasypyga or true Apes, as contradistinguished from the Scleropyga or Gibbons 
(‘‘ natibus nudis, callosis ”’). 
The Dasypyga have been divided, as we have seen, into two genera, Pithecus, Geoffr., 
and Troglodytes, Geoftr. To the first belong the Simia Satyrus of Linnzus, or Orang-utan, 
characterized by long arms (reaching to the ankles), a short thumb of the hind hand, 
sometimes wanting the ungual phalanx and nail, never reaching the end of the meta- 
tarsal of the second toe: the ligamentum teres of the hip-joint is absent; there are 
twelve pairs of ribs; the superorbital ridge is slightly produced; the premaxillaries 
become anchylosed during the second or permanent dentition ; the tuberculate grinding 
surface of the molars is rugose. The second genus is represented by the Chimpanzee 
Jacchus, Geoffroy, and Midas, Geoffroy, form a group equivalent to the genera Cynocephalus, Cuy., Innuus, Cuv., 
Cercopithecus, Erxl., Semnopithecus, F. Cuv., Hylobates, Ilig., and Simia, Illig. I have therefore given, in the 
text, a few remarks on the value of the group formed by the last two Illigerian genera, and on the grounds for a 
division of Simia, Illig., into two genera. 
* Op. cit., ‘Tabula Synoptica Simiarum,” p. 4 (1820). 
