1895.] LOEIUS FIAVOPALLIATTIS AKD PSITTACUS EEITHACUS. 385 



coincides with the uppermost (and most concave) part of the post- 

 axial margin of the external auditory meatus. Below this, again, 

 is the nearly straight lower part of this margin, which inclines 

 slightly inwards as it descends, and is bounded inferiorly by the 

 sudden out-jutting of the zygomatic process of the quadrate for 

 the zygoma together with the posterior end of the latter. Below 

 this is the lateral outline of the quadrate, which is nearly straight 

 and vertical to the rounded inferior end of that bone. 



In L. Jlavopalliatus the median concavity of the dorsal margin 

 is less marked ; the lateral margin is generally similar to that of the 

 other species save for the much less, relative as well as absolute, 

 extent of the part formed by the quadrate below its zygomatic pro- 

 cess, and that the sphenotic process (sph) is seen projecting out- 

 wards beyond the posterior margin of the external auditory meatus. 

 The suprameatal process (sm) projects sharply outwards. 



Fig. 11. 



sm 



Postaxial aspect of skull of Lorius Jlavopacliaftis, 



Ir. Lambcloidal ridge. 



oc. Occipital foramen. 

 par. Paroccipital process. 

 po. Postorbital process. 

 pt. Palatine. 



q. Quadrate. 

 sm. Suprameatal process. 

 spk. Sphenoidal process. 

 g. Zygoma. 



The inferior margin of the cranium, thus seen, is, in P. erithacus, 

 formed externally by the two zygomatic processes of the quadrate. 

 Next within comes the inferior border of each quadrate, and then 

 that surrounding the deep and sudden notch which divides each 

 quadrate from the paroccipital process, which does not descend as 

 much as does the quadrate. The median part of the inferior 

 margin (apart from the palatines) presents a low arch medianly 

 interrupted by the projection downwards of its keystone — the 

 basi-occipital with its condyle. 



This margin in L. Jtavopalliatus is similar save that the par- 

 occipital processes descend almost as much as do the quadrates. 



On this view the palatines are seen descending and diverging at 

 Peoc. Zool. Soc— 1895, No. XXV. . 25 , - - 



