PASSEHES 181 



intrinsic muscles are wide and thin, nearly in contact with 

 each other before, and behind they are attached to the first 

 semi-rings everywhere but at their tips. Pitta has a much 

 simpler syrinx, approximating so far to that of the Eurylae- 

 midse ; the muscles are thin and accurately median in inser- 

 tion. Pitta is unique among passerine birds by reason of 

 the deep temporal fossae of the skull, which nearly meet 



Fig. 87.— Stmnx of PhiUpitta. Fig. 88.— SiiBiNX op Philepitta. 



Side View. (After Fokbes.) Fkont View. (Aftek Pokees.) 



behind, in a way that is seen in some other birds not 

 passerine. 



In the New Zealand Xenicus and Acanthisitta ^ there are 

 A B 



Fig. 89. — Sybinx of Xenicus. A. Fkont View. B. Back View. 

 (Aftek Forbes.) 



only ten rectrices, twelve being the number characteristic of 

 the majority of the Passeres. The syrinx of Xenicus as seen 

 in the annexed figure is quite typically mesomyodian. The 

 last few tracheal rings are consolidated into a large box, to 

 the top of which the intrinsic muscles (small and median in 

 insertion) are attached. 



' Forbes, ' On Xewietis and Acanthisitta,' &c., P. Z. S. 1882, p. 569. 



