1905.] MR. R. I. POCOCK ON A HAINAN GIBBON. ' 169 



Glareola and Thinocorus are like Scolojxix, but have a slip to the 

 great toe. Vanellus and GcdUnago are exactly like Scolopax ; 

 Charadrius and Himantojyus are also identical with it, except 

 that there is no great toe. 



The conditions of these tendons in Limicolse are similar and 

 much alike, being not far removed from the condition that I 

 take to be archecentric or primitive for Birds. But in the group 

 there is a tendency to lose or reduce the great toe, and that 

 loss or reduction has produced modifications which are similar 

 in character and very easy to derive from the primitive type. 



Summary. 



With the exception of CEdicneimcs, the Limicoline birds 

 examined, so far as relates to the characters dealt with, show a 

 definite and coherent series of modifications. The group is 

 moving, or has moved, along the same anatomical lines. The 

 limits of its variations overlap in a special way the variations 

 displayed by Gulls, and in a general way those exhibited by 

 Gruifoi'm birds. 



References. 



(1) Beddard, F. E. — The Structure and Classification of Birds. 



1898. 



(2) FtJRBRiNGER, M. — Untersuchungen zur Morphologie und 



Systematik der Vogel. 1888. 



(3) Gadow, H. — " Aves" in Bronn's Thierreich. 



(4) Mitchell, P. Chalmers. — " Quintocubitalism in the Wing of 



Birds." Journ. Linn. Soc, Zool. vol. xxvii. p. 237. 



(5) Mitchell, P. Chalmers. — " Anatomy of Kingfishers." The 



Ibis, 1901, p. 97. 



(6) Mitchell, P. Chalmers.- — " On the Intestinal Tract of Birds." 



Trans. Linn. Soc. ser. 2, Zool. vol. viii. p. 173. 



(7) Mitchell, P. Chalmers. — " On the Anatomy of Gruiform 



Birds." Proc. Zool. Soc. Lond. 1901, vol. ii. p. 629. 



6. Observations upon a Female Specimen of the Hainan 

 Gibbon (^Bylobates hainanus), now living in the Society's 

 Gardens. By H. I. Pocock, F.L.S., F.Z.S., Super- 

 intendent o£ the Gardens. 



[Received May 16, 1905.] 



(Plate Y.*) 



Age at Maturity. 



On Jan. 26, 1904, the Society received on deposit a female 

 specimen of the Hainan Gibbon, the property of Mr. E. H. de 



* For explanation of the Plate, see p. 180. 



