34 



PHOF. D ARCY W. THOMPSON ON THE 



[Jan. 17, 



quadrate articulation. The outlines of the temporal and digastric 

 fossre are, as shown in the diagram, extremely different from those 

 of both Psiitacus and Coracopsis. The shaft of the quadrate is 

 extremely stout, its inner border running down evenly into the 

 mass of bone above the quadrato-jugal cup ; the anterior process 

 is short but stout; the inner head of the bone is of exceptional 

 size. Alone among all the forms I have examined, the interorbital 

 vacuity is completely absent. I feel convinced that further 

 examination of better material will show Basyptilus to be a very 

 peculiar and isolated form. Coracopsis is very similar to Eclecfus, 

 and this resemblance will be discussed in dealing with the latter 

 form. 



Family Pal^ornithtNjE. 



Of the forms grouped as Palaeornithinas, I have studied Eclectus 

 (fig. 29), Geoffroi/us, Tan)jg>mfhns (figs. 30, 31), PohjteUs (fig. 32, 

 p. 35), Aprosmictus (tig. 33, p. 35), Pi/rrhuhpsls (figs. 34, 35, 



Fig. 29. 



Eelectus cardinalis. 



Fig. 30. 



Tam/gnathus mcgalorhynchus. 



p. 36), Agapornis (fig. 36, p. 37), and Paleoriiis ; I regret in 

 particular the want of Loricidus. Of these, it is clear that 

 Polytelis, Aprosmictus, and Pyrrhulopsis stand apart from the first 



