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 
11 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 1°5 
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 kone is smooth and strong. The facet for the 
basipterygoid is in the middle of the shaft, and lies mainly outside 
an ascending flange 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 Corythaiv, but the jugals are. 
These latter bones are not hinged in Steatornis( Plate XVII. fig. 3,7) 
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 approach the quadrate, into which they fit by gomphosis. 
The hinder part of this jugal bar is formed by the quadrato-jugal 
(qj.). The three 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 (q.) 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 Striw (Ketupa) ceylonensis these “heads” of the otic 
process are 12°5 millim. across; in Sfeatornis 7 millim.; in Cory- 
thaiz 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 oblique and pedate, and its body is 
deep and rather square; the cup for 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 ¢rochlea looking inwards and back- 
wards, and an anterior oval, convex condyloid tract 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 
