350 MK. p. CHALMERS MITCHELL OX THE [May 7, 



2. On the Anatomy of Chauna chavaria. 

 By P. Chalmers Mitchell, M.A., F.Z.S. 



[Eeceived May 6. 1895.] 



Owing to the kindness of my friend, the Prosector of the Society, 

 Mr. P. E. Beddard, I have had the opportunity of examining the 

 anatomy of a female specunen of Chauna chavaria, the Crested 

 Screamer. Garrod (1) has given an account of the anatomy of 

 Chauna derliana ; Mr. Beddard and I (2) have puhhshed the results 

 of our investigation of Palamedea comuta ; but less has been 

 written about Chauna chavaria, and I have thought it worth while 

 to examine carefully this third of the three known species of the 

 Palamedeidae. 



External Characters, 



The skin was very emphysematous, even upon the tibia, thus 

 differing from C. derbiana, but, as in that and in Palmedea, there 

 was a triangular space on each shoulder undistonded by air. 



The number of rectrices was 12, as in C. derbiana, not 14 as in 

 Palamedea. The wing was aquintocubital as in C. derbiana and 

 in Palmedea \ 



As Nitzsch states, there is a small aftershaft on some of the 

 feathers on the nape of the neck. This is absent in other regions. 



The oil-gland is natiform, and is tufted and covered by feathers. 

 It has two large apertures separated from each other by a narrow 

 Mne of feathers. 



Viscera of Abdomen. 



I have little to add to Beddard's description of the septa (3). 

 As in Palamedea, the lobes of the liver are not shut off from the 

 subomental space. The falciform septum is nearly median and 

 extends unusuallj'" far back, reaching to within half an inch of the 

 ends of the pubes. The horizontal septum was a stout brown 

 membrane attached to the pubes behind and forking over the 

 stomach. The oblique septa stretched from the pubes to the 

 pericardium, and contained numerous strias in their thick walls. 



The lobes of the liver were more nearly equal in size than in 

 Palamedea. The gall-bladder was large, and the cystic, hepatic, 

 and single pancreatic ducts entered the summit of the ascending 

 loop of the duodenum exactly as we described in Palamedea (2), and 

 not at the position described by Garrod for C. derbiana (1). 



The proventriculus (s) was very capacious, and, as Garrod de- 

 scribes m C. derbiana, the glandular area forms a narrow zone round 

 the anterior end and a long triangular patch stretching down on the 

 side. In this respect, certainly, the proventriculus is, as Garrod 



' In our paper on Palamedea (P. Z. S. 1884, p. 536), by an oversight, we stated 

 that the wing was quintocubital. We have examined three specimens and 

 fpund the fifth featlier absent in each. 



