1895.] LOEirS FliAVOPALLIATUS AJSD PSITTACUS EEITHACTS. 383 



lachn-mal is broader, especially at the dorsal margin of the ex- 

 ternal lachrymal groove. Its greater length causes it also to be 

 more visible alongside of the zygoma. 



The paroccipital processes are much more -s-isible than in P. eri- 

 thanis, and descend, very decidedly, below the quadrates. The 

 palatine and pterygoid angles are much as in P. erithacm. 



When the quadrate is removed we find, in both species, that the 

 glenoid fossa of the squamosal is visible at the root of the ventral 

 surface of the sphenotic process. \Yithin this is a narrow rough 

 surface which separates the glenoid fossa from the smaller, more 

 internal, fossa of the pro-otic, which serves for the articulation of 

 the inner tubercle of the quadrate. 



Fig. 9. 



Anterior aspect (prosopium being removed) of Psittacus erithacus. 



opf. Optic foratnen. 



jpar. Paroccipital process. 



po. Postorbital process. 



sp. Septal process. 



sph. Sphenotic process. 



tg. Trangyerse groove. 



tr. Transverse ricJge. 



bts. Basi-beinporal shield. 

 cr. Crucial ridge. 

 ipc. Inner precranial foramen. 

 I. Lachrymal, forming the pre- 

 orbital prominence. 

 oc. Occipital condyle. 

 ope. Outer precranial foramen. 



On the removal of the prosopium, the anterior aspect of the 

 cranium shows mediauly, in P. erithacus (fig. 9), the prominence 

 of the base of the cranial septum, with the slightly marked septal 

 process {sp). On either side of this median keel are the large 

 olfactory apertures. 



Dorsad is the surface of the frontal and beneath it the trans- 

 verse groove (tg) for the dorsum of the prosopium, the fossae at 

 the outer ends of which receive its lachrymal processes. Beneath 

 these two fossae is the swollen preaxial surface of the lachrymal (/) 

 with its depending process transversely grooved externally. 

 "Within the lachrymal on each side, and just mesiad of the fossa for 



