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 vertebrae to a non-projecting ' os coccygis ;' 

 the feeble met- and an-apophyses in the lumbar vertebrae 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 cseci,' are characters of the 

 Pithecina, Is. Geolfr. 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 

 afiinities 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, Geoffr. To the first belong the Simla Satyrus of Linnaeus, 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, Geoffrey, form a group equivaleut to the genera Cynocephalus, Cuv., Innuus, Guv., 

 Cercopithecus, Erxl., Semnopithecus, F. Cuv., Hylobates, lUig., and Simla, Illig. I have therefore given, in the 

 text, a few remarks on the value of the group formed by the last two lUigerian genera, and on the grounds for a 

 division oi Simla, Illig., into two genera. 



' Op. cit., "Tabula Synoptica Simiarnm," p. 4 (1820). 



