•] 



CRANIAL OSTEOLOGY OF THE PARROTS. 



17 



deep excavation behind the squamosal or zye;omatic process wliich 

 is so marked and exceptional a feature in this bird, but which we 

 now discover to be a huge development of the tiny groove in 

 Psittacus, and of our Ilird fossa in Corvus ; and we further see that 

 the opposite or inner Mall of this last fossa, which so deeply over- 

 laps and overhangs the bead and shaft of the quadrate, is precisely 

 comparable to that little process which did likevi'ise, but to a 

 slight degree, in the Grey Parrot and the Crow. 



Fiff. 6. 



Nestor meridlonalls, for comparison with figs. 4 & 5. 

 (Letters as in previous figures.) 



The tyu) panic cavity is of moderate size, A^idely open when we 

 look at it from in front, but in its lateral aspect almost concealed 

 by the forward growth of the scroll-like posterior wall ; the cavity 

 has a deep posterior recess, descending to near the apex of the 

 paroccipital process, where is a large oval foramen for the so-called 

 tensor tympani. The lower and anterior border of the meatus, 

 as it bends upwards, quite distinctly shuts out the region of the 

 quadrate articulation from the boundaries of the tympanic cavity. 



The quadrate bone (tig. 7) Las two widely separate capitula, the 



Fio-. 7. 



Quadrate bone of Nestor meridionalis. 

 (Letters as in previous figures.) 



inner one being in a considerable degree the smaller; but the 

 double socket for these heads, though constricted in the middle, 

 Proc. Zool. Soc— 1899, No. II. 2 



