168 MR. W. K. PARKER ON STEATORNIS CARIPENSIS. [Apr. 2, 



In the large specimens the basipterygoids have a facet for their 

 perfect joint with the pterygoids 4-5 millim. in extent ; these two 

 oblongo-oval condyloid tracts are 8 millim. across in front, and 

 1 1 millim. behind ; they are wider proximally than at their articular 

 face, and project 2 millim. at their hinder notched margin. The 

 sphenoidal rostrum is 5*5 millim. wide between their fore part, and 

 2 millim. over the palatine groove. 



The pterygoids {pg.} are 11 millim. long, and measure from \'b 

 millim. to 2*5 millim. in breadth. They approxmiate at a few degrees 

 more than a right angle ; in the Trogon, at a few degrees less ; this 

 greater divergence is due to the general extension in breadth of the 

 hind skull ; and the same thing is seen in Owls. The fore part 

 of the pterygoid is oblique and tridentate, it overlaps the palatine ; 

 the epipterygoid forms a low triangle ; the whole bar is arched 

 upwards, and the bone is smooth and strong. The facet for the 

 basipterygoid is in the middle of the shaft, and lies mainly outside 

 an ascending flatige of the bone, so that it works outside the fixed 

 condyloid facet of the basipterygoid ; it is only two thirds the length 

 of that fixed facet, and moves beyond it, in front and behind. Thus 

 the capsular ligament must be loose and elastic, as in the oblique 

 facets in the mid-region of the neck of Buceros and other Cuculines. 



The palatines are set on more suddenly to the "rostrum," or 

 upper beak, than in the Trogon, where, however, they are not 

 hinged; they are not hinged in Corythaix, but the jugals are. 



These latter bones are not hinged in ;S'^eaforw?A(Plate XVII. fig. 3,^') 

 and are very slender ; first depressed, where they begin at the fore part 

 of the jugal process of the maxillary, and then compressed, where 

 they a})proach the quadrate, into which they fit by gomphosis. 

 The hinder part of this jugal bar is formed by the quadrato-jugal 

 {q-j.)- The tliree elements of this feeble cheek are all ankylosed 

 into one elastic needle of bone, which, in the middle, is only 6*5 

 millim. thick. The quadrate (g.) is a well-formed normal bone, in 

 harmony with the Owl-like breadth of the hind skull ; the setting 

 on of the double hinge, or " otic process," is wide and transverse, 

 the inner head being only about 2'5 millim. behind the outer. In 

 the large Strix (Ketupa) ceylonensis these " heads " of the otic 

 process are 12"5 milHm. across; in Steatornis 7 millim.; in Cory- 

 thaix 5 millim. Relatively to the size of the skull, Steatornis has 

 its otic process nearly as wide as in the Owl. The quadrate has an 

 average " orbital process ; " it is obhque and pedate, and its body is 

 deep and rather square; the cup tor the end of the jugal bar is 

 neat and pedunculate ; the knob for the end of the pterygoid is 

 well-formed ; and the inferior condyle, as usual, is double. 



This latter part has a hinder trochlea looking inwards and back- 

 wards, and an anterior oval, convex condyloid ti'act which is in a 

 line with the oblique pterygoid, and just reaches its joint, which is 

 a cup and ball. 



The action of a palate like this is somewhat less rapid, and the 

 parts themselves are much lighter and slenderer, than in many of 

 the Cuculines, or in the Parrots, generally. This part is rather 



