1895.] AJfATOMT OF CHATWA CHATAEIA, 353 



Windpipe. 



I have little to add to Beddard's description of this organ (3). 

 The two pairs of extrinsic muscles were as he found them. The 

 syrinx was notched only at the back, as in C. derhiana. None of 

 the bronchial semirings were ossified. 



The Heart. 



This organ was typically avian. The only peculiarity \^orth 

 noting was in the I'ight auriculo-ventricular valve. In the smaller 

 part of the valve, which Beddard and I have identified with the 

 septal flap of the Alligator's similar vahe, I found a small tendinous 

 area. The edge of the flap was muscular, one strand of muscle 

 running to the bridge of muscle which binds the two flaps to the 

 wall of the ventricle. Another band of muscle passed from the 

 lower edge of the valve to the septal Mali of the ventricle, exactly 

 as in the Ostrich and in the Alligator. 



Tlie Buccal Cavity. 



The tongue was identical with that of C. derhiana, as described 

 by Garrod, 



Between the rami of the mandible, anterior to the mylohyoid 

 anterior, lay a pair of large pear-shaped glands opening into the 

 floor of the mouth at the anterior end, just behind the lower beak, 

 by a number of small apertures on each side of the middle line. 



Mtologt. 



In my account of tliis I shaU follow the description recently 

 given by Beddard and myself of the myology of Palamedea (2), 

 as in the main the two birds are very closely alike. 



In the muscles of the neck and ti-unk the only point worth 

 noting is that the new muscle described by us as the costo-stemalis 

 externus was also present in Chauna chavaria. It arises by a flat 

 tendon from the third, fourth, and fifth ribs and is inserted to the 

 costal edge of the sternum, less than half an inch from the 

 posterior end. As in Palamedea it may be taken as replacing 

 physiologically, to a certain extent, the absent uncinate processes. 



Head-Muscles. 



Dei'mo-temporalis and biventer maxilla as in Palamedea. Digastric 

 or depressor mandihidce, as in Palamedea, consists of two parts. 

 The external portion arises by a strong tendon from behind the 

 external auditory meatus ; it runs downwards and forwards, and is 

 inserted fleshy along the upper edge of the angulare. The inner 

 portion is almost entirely tendinous ; its origin is below that of 

 the outer portion and its insertion is to the ventral and median 

 side of the origin of the angular process. 



Temjjoralis consists of four clearly separated portions. The 

 Pboc. Zool. Soc— 1895, No. XXIII, 23 



