454 STJRUCTUEE AND CLASSIFICATION OF BIRDS 



three species. In Palamedea the flexor longus hallucis is 

 slender, and gives off a vinculum to the flexor communis 

 tendon, before supplying the first digit ; in Chauna derhiana 

 there is no branch to the first digit at all ; Chauna chavaria 

 is like Palamedea, but there are two 

 distinct vincula. 



The palate (of Ch. chavaria at any 

 rate) is provided vyith three longitudinal 

 rows of papillae ; the tongue is just over 

 an inch long, and its base is edged with 

 spines. There is no transverse constric- 

 tion or oblique groove, such as is found 

 in many anatiform birds. The proven- 

 triculus is peculiar; there is a narrow 

 zone of glands round the oesophageal 

 aperture, from which a broad triangular 

 patch extends down one side of the 

 cavity. The gizzard is decidedly small. 

 The lobes of the liver are more nearly 

 equal in size in Chauna than in Pala- 

 medea ; in all there is a conspicuous gall 

 bladder. The cceca (fig. 213) are in 

 some respects unique in structure ; they 

 are in the first place large, measuring 

 three inches or so in length ; they are 

 sacculated by a single band. 



The windpipe agrees with that of 

 some of the Anseres in having two pairs 

 of extrinsic muscles : ^ the upper pair is 

 inserted into the middle of the membrane, which runs 

 between the coracoid and the corresponding limb of the 

 furcula ; the lower pair close to the costal processes of the 

 sternum. The intrinsic muscles cease some little way in 

 front of the syrinx. 



The prebronchial and subbronchial air sacs are, in Gh. 

 chavaria at least, much divided up, as, in the storks. In 



' Apparently first noted by Ceisp, ' On the Visceral Anatomy of the Screamer,' 

 P. Z. S. 1864, p. 14. 



Fig. 214. — Windpipe oi 

 Palamedea (atteb Bed 



DAKD AND MiTOHELl). 



