1889.] MR. W. K. PARKER ON STEATORNIS CARIPENSIS. 167 
3 millim. across, and together take up a space of 11 millim., 
measured across. They then narrow into 2°5 millim. and enclose an 
oval common “middle palatine foramen” or open space 9 millim. 
long and 6 millim. wide ; the fore end of this space is enclosed by the 
maxillo-palatines and septum nasi, and is, indeed, the middle notch 
Just spoken of. This space is enclosed behind by the two palatines, 
which meet and form an oblique suture 1°5 millim. in extent. 
This second part of the hard palate in this “doubly Desmogna- 
thous” bird is 8 millim. across; behind it the palatines narrow 
in again, until their lower part is a mere ridge ; but they have curled 
round now, and formed the low and short ‘‘ethmopalatine,” or 
ascending processes, which run under the sphenoidal rostrum for a 
distance of 6 millim., and are ankylosed together. Behind, the 
two coalesced palatines are only 3-3 millim. across, where they articu- 
late with the pterygoid. The outer edge of each palatine is sharp, not 
limbate ; it is bevelled into an edge from the sub-mesial thickest part. 
I have spoken of the prepalatine bars as laths; the middle and 
hinder part is like a shaving, coiled obliquely, so that the edges of 
the two bones meet below, in front, and above, in their hind part. 
They thus enclose the naso-palatine passages (i.n.), flooring them in 
front for a short distance, and then roofing them, behind, for three 
times that extent. The concave opening of these passages behind the 
short posterior hard palate is elliptical, 9 millim. by 4°5 millim. The 
edge of the two bones enclosing this space is limbate, and corresponds 
with the inner edge of a grooved palatine bone; here, there is no 
groove, but the bone curls upwards at once, to pass into the ascending 
plate. This is much more primitive, or simple, than what is seen 
in the Trogons, where they do not unite to form a second part of 
a hard palate, and have a groove and some angulation of their outer 
edge. 
Steatornis has two vomers(v.), each 5°5 millim. long and 1 millim. 
wide ; they are sharp at both ends. The hinder bone has had its 
distinctness obliterated by ankylosis; it is probably a ‘ medio- 
palatine,” like that seen in Caprimulgus, Owls, &c.; this vome- 
rine bone, now, forms merely an upper, partial septum between the 
naso-palatine passages. In a membranous tract in front of the 
triangular end of the fused vomer there is, at a little distance, 
a similar bony tract—an ‘‘antero-median vomer.” The supero- 
external edge of each palatine, for an extent of 3-5 millim., is 
formed by the “mesopterygoid” increment; so that the short 
trough, 4 willim. in extent, in which the sphenoidal rostrum (pa.s.) 
lies, is formed by three pairs of bones; that rostrum runs free of 
this groove for 7°5 millim., its projecting point is 3 millim. 
behind the vertical line of the hinge, and of the notched hind edge 
of the septum nasi. It is extremely unlike an Owl in this respect, 
in which bird the hinge-notch is shallow and of great extent; the 
rostrum of the sphenoid ends much further backwards in that bird, 
having no projecting spike in front. The hind part of the sphenoidal 
rostrum, with its basipterygoid processes (J.pg.), may be described 
now, because of the relation of the latter to the pterygoids. 
12* 
