Vol xxn SxODGRAss, Geospizii^ Coconiif, and CcifJiidia. 4^S 



poral crest extremely large and high up on side of cranium, 

 curves upward and posteriorly from posterior angle of base of 

 postfrontal process, posteriorly it curves downward and ends in 

 rather prominent process above ear. This crest is greatly larger 

 than in such thick-billed genera as Cardinalis and Zamelodia (PI. 

 XVII, Fig. 3). In these latter forms also the crest is far below 

 the dorsal profile of the cranium. 



Temporal area very long, its length, from one extremity of tem- 

 poral crest to the other, equal to distance from anterior end of 

 crest to nostril. This gives an extremely great postorbital length 

 to the skull, the whole configuration of the cranium being very dif- 

 ferent from that of any ordinary Passerine skull. Surface of tem- 

 poral area slightly depressed and roughened, lacking the glazed 

 appearance of top of skull. Squamosal process very large, its 

 . lower end refiexed posteriorly and lying well behind tip of post- 

 frontal process. In Cardinalis the tip of the squamosal process is 

 slightly in advance of the tip of the post-frontal process. Crota- 

 phyte depression between post-frontal and squamosal processes 

 wide and deep. 



Tympanic region flat and almost vertical. Lambdoidal crest 

 prominent, but smaller than temporal ; median part horizontal ; 

 lateral parts deflexed and then curved inward, terminating on 

 each side at base of a prominent mastoid process back of lower 

 part of ear opening. This mastoid process is absent or but 

 poorly developed in other Passerine genera examined as well as 

 in other species of Geospiza. Posterior surface of skull receding, 

 /. 6'., when zygomatic bar is horizontal, it. extends downward and 

 slightly forward below lambdoidal crest. 



Interorbital septum complete, very thick, and composed of a 

 double wall. Preorbital parts of skull of ordinary Fringillid 

 character. Rim of orbit rather thick and heavy in appearance 

 on account of deflexion of lateral part of interorbital area on top 

 of skull. In Zamelodia, Cardi?ialis, Pipilo^ Carpodacus , Astragali- 

 nus, and in other species of Geospiza the interorbital surface is 

 evenly concave, giving the orbital rim a much thinner appearance. 

 On posterior wall of orbital cavity are three conspicuous, vertical, 

 crest-like ridges. Lower end of outer one forms a process visible 

 laterally, projecting from lower part of crotaphyte depression. 



