Fig. 
un) 
te 
g 
ig. 4a. 
&. 5d. 
OF THE PALATE OF THE NEOGNATH A. By5)// 
g. 4. Lateral view of the pterygoid of Tetrapteryx paradisea. The hemi- 
pterygoid and palatine bear the same relation to the main body of the 
pterygoid as in Oceanodroma (fig. 2). 
In this figure, which represents the external lateral view of fig. 4, the 
hemipterygoid element is seen to be more degenerate than in 
Pygoscelis (fig. 3a), and the vomer is in consequence supported 
entirely by the palatines. 
. 5. Lateral view of the pterygoid of a nestling of Steatornis caripensis, 
wherein the hemipterygoid element has not yet segmented off from 
the main shaft. 
. The lateral view of the pterygoid of an adult Steatornis caripensis , 
The distal end of the pterygoid has now segmented off to form the 
hemipterygoid. It is connected with the main shaft by a sigmoid 
articulation, but remains traceable throughout life by reason of the 
fact that its distal end projects above the palatine. 
Ventral aspect of fig. 5a, showing the transverse articulation with 
the palatine and fused hemipterygoid element. 
. 6. Lateral view of the pterygoid of the Rook (Corvus frugilegus). The 
hemipterygoid just reaches the vomer. Later, on its fusion with the 
palatine, the articulation with the main body of the pterygoid is 
oblique, not transverse as in the majority of Neognathe. 
7. Lateraljview of the pterygoid of Mega/ema marshallorun. Compared 
with fig. 6 it will be seen that in Megalema the pterygoid has 
reverted to the original, Paleognathine, unsegmented condition, the 
hemipterygoid being continuous with the main shaft and extending 
forward to support the vomer, which is entirely free from the 
palatine. , 
. 8. Lateral view of the"pterygoid of Bucco Dysoni. The pterygoid, as in 
fig. 7, is unsegmented. The vomer is vestigial or wanting. By 
further specialization the palatine has almost completely fused with 
the pterygoid, only a slight cleft marking the distinction between 
the two. 
Fig."8 a. Ventral view of fig, 8, showing the last traces of an originally trans- 
yerse palato-pterygoid articulation. 
ExpnanatTion oF Lerrers. 
h.pt.=hemipterygoid. 
inf.t.foss.=inferior temporal fossa (quadrato-jugal fossa). 
m2x.p.=maxillo-palatine process. 
pa.=palatine. 
par,.=parasphenoidal rostrum. 
p.p mx.=palatine process of premaxillary. 
pt.=pterygoid. 
vo. =vomer. 
