MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 187 



more transversely extended than in Man and is more reniform ' ; the concavity also 

 between it and the styloid process is deeper (PL XXXVIII. figs. 5 & 6). This last- 

 mentioned process appears to vaiy much as to size, from individual to individual 

 (PL XXXVIII. figs. 2 & 6 s) ; but it is never so long, compared with the total length 

 of the ulna, as in Man and the Chimpanzee^. 



The groove for the tendon of the extensor carpi ulnaris is generally very little marked, 

 and less so than is the case in Man or the Gorilla, so far as I have been able to observe. 



Maims. (Plate XLII.) 

 This segment of the skeleton attains, in the Orang, a greater absolute length than 

 it does in Man or Troglodytes. Its proportion to the spine (measured as before) is also 

 greater ; but those borne by it to the rest of the pectoral limb and to the radius are less 

 in the Orang than I have found them to be in the Chimpanzee, though greater than in 

 Man or in the Gorilla. In its slenderness the manus of the Orang more resembles that 

 of the Chimpanzee than that of the Gorilla or of Homo. 



Carpus. 



This segment differs very importantly from that of the higher forms, in that, as is 

 well known, there is a separate and distinct ninth carpal bone^ the os intermedium. 



The proximal row of carpal bones forms a double arch, as in Man and Troglodytes. 



The vertical arch (with its convexity proximad) is rather more acute than in Man ; 

 but the OS pislforme being small, its outline is not interrupted by that bone, as it is in 

 Troglodytes, and so far it resembles more the homologous arch of the human hand 

 than does the vertical carpal arch of the last-named genus (PL XLII. fig. 1 ). 



As in the higher forms, the carpus in the Orang articulates directly with the radius 

 only. 



ScapJtoides. (Plate XLII. figs. 2, 3, 4.) 



This bone is very much narrower antero-posteriorly (from dorsum to palm), and 

 relatively much more transversely extended, than in Man, and there is no transverse 

 dorsal groove; so that the scaphoid of the Orang has very much the appearance that 

 that of Man would have, if the part anterior to (or on the distal side of) his dorsal groove 

 were cut away. Indeed the whole scaphoid of the Orang appears to answer to only 

 the upper or proximal part of the human scaphoid' and of that of Troglodytes. It 



' Owen, Trans. Zool. Soe. vol. v. p. 7. 



2 In a mounted specimen of the GoriUa in the British Museum, this process is very short indeed. 



' Pointed oat hy W. VroUk, Eecherches d'Ant. Comp. sm- le Chimpanse, p. 13 ; and Todd's Cyclopxdia, 



vol. iv. p. 203. 



^ See Do Blainville, Osteographie, " Primates : Pithectis," p. 16 ; Professor G. M. Humphry, Limbs of Verte- 

 brates, 1860, p. 4; Professor Huxley, Hmiterian Lectures, Medical Times, 1864, voL i. p. 565 ; and Dr. 

 Lucae, Abhandlungen von der Senckenbergischen naturforschondcn Gesellschaft, 1865, vol. v. p. :U1. The 



2 d2 



