1 6/3. j ANATOMY OF STEATORNIS. 531 



an inch long, slender and quite blended with the palatines ; its ante- 

 rior pointed extremity advances as far forwards as the posterior 

 border of the median palatine symphysis mentioned above. The 

 posterior external angles of the palatines, so large in Caprimulgus 

 and Podargus, are not developed. The basipterygoid facets are 

 large. In the eye the sclerotic ossifications are not considerable, as 

 in the Owls, being not at all unusually developed. 



In the atlas the cup for articulation with the occipital condyle is 

 incomplete behind; and the odontoid process of the axis is situated 

 near its posterior margin. In this conformation, the classificational 

 importance of which was first pointed out by Mr. Parker, Steatornis 

 agrees with the Strigidee and the Caprimulgidge, but not with the 

 Cypselidse, in the one or two cases which I have had the opportunity 

 of observing. 



The well-known peculiarities of the sternum do not seem to point 

 definitely in any special direction ; and in the other bones 1 have not 

 observed any demonstrable tendencies. 



Digestive organs. — The tongue is thin, smooth, and triangular ; it 

 is \ inch broad at its base, and f of an inch long ; the posterior 

 angles are prolonged backwards for ^ of an inch as angular processes 

 with small papillae on them ; the posterior border is simple. The 

 oesophagus is capacious and uniformly cylindrical, with longitudinal 

 plications in its mucous membrane. The proventriculus is zonary 

 and well developed, the largest of its component glands, which are 

 slightly racemose, being -| of an inch long. The stomach forms a 

 thin- walled, globose, capacious gizzard, with its mucous membrane, 

 as usually, longitudinally plicated. The intestines are 22 inches 

 long, capacious throughout, and especially so near the pyloric 

 portion ; the biliary and pancreatic ducts open into it 2| inches 

 from the pylorus, at the bend of the duodenal loop. The two in- 

 testinal cceca are 1| and lg inch long, slender, and a little broader 

 at the caecal than at the open ends ; they are situated 2 inches 

 from the cloaca. 



The trachea is a little more capacious above than below. As in 

 many birds, the separate rings of which it is composed are not so 

 deep in the middle line as they are laterally ; and as in each ring the 

 upper and lower margins of one side in one ring, and of the other 

 side of the next above and below, are slightly everted, whilst those of 

 the other half are inverted to the same extent, when the rings are 

 superimposed they produce the appearance seen in the accompanying 

 drawing, as if each ring were narrow on one side and broad on the 

 other. The syrinx (fig. 3, p. 532), as has been described by others, is 

 extremely peculiar, because it is formed in each bronchial tube, instead 

 of at the bifurcation of the trachea. The trachea bifurcates at its 

 lower end much in the same way that it does in Mammalia ; and each 

 bronchus continues down towards the lungs as a cylindrical or 

 slightly flattened tube, composed of simple and entire rings of carti- 

 lage. In a specimen that I once saw, there were fourteen of these 

 rings on each side ; but in the one before me, which is figured here, 

 the bronchi are not equal in length, the left bronchus containing 



34* 



