478 SLONAKER. [Vol. XIII. 



Robin (Merula migratoria, PI. XXVII, Fig. 17, and PI. XXVIII, Fig. 28). 



Blue-Bird (Sialia sialis, PI. XXVIII, Fig. 29). 



Kinglet (Regulus satrapa, PI. XXVIII, Fig. 30). 



Snow-Bird (J unco hyemalis, PI. XXVIII, Fig. 31). 



Crow (Corvus americanus, PI. XXIX, Fig. 52). 



Blue Jay (Cyanocitta cristata, PI. XXIX, Fig. 53). 



Night Heron (Nycticorax nycticorax, PI. XXVII, Fig. 23). 



A number of birds possess a medium fovea, as seen in the 

 pigeon (Columba livia domestica, PL XXVIII, Figs. 37, 38). 

 It is readily observed surrounded by a well-defined area. It 

 varies somewhat in depth in the same species, as is shown in 

 this case. Fig. 37 represents a medium fovea, while Fig. 38 

 would be classed as shallow. 



Most of the Gallinas which I have examined possess medium 

 to very shallow fovea. The quail (Colinus virginianus) and the 

 partridge (Bonasa umbellus) each possess a medium fovea, 

 while in the turkey (Meleagris gallopavo, PL XXVIII, Fig. 35) 

 and the guinea hen (Numida pucherani, PL XXVIII, Fig. 36) 

 it is shallow. In the last case the depression is so slight as to 

 scarcely deserve the name of fovea. Chievitz mentions an area 

 nasahs and a questionable fovea in the hen (Gallus domesticus). 

 I have succeeded in finding only a very slight thickening. 



Screech Owl (Megascops asio). 

 Barred Owl (Syrnium nebulosum). 



These owls possess a single deep fovea surrounded by a 

 sharply defined round area which differs from those just 

 described only in position. It is located on the temporal side 

 and above the nerve entrance in such a position as to function 

 in binocular vision. The nerve entrance is similar in position 

 to that of other birds, but the pecten is much smaller in pro- 

 portion to the size of the eye (PL XXIX, Fig. 55, and PL 

 XXVII, Fig. 10). 



Goose (Anser cinereus domesticus). 



The goose possesses a shallow fovea nasalis surrounded by a 

 round area situated on a band-like area extending horizontally 

 through the retina. The fovea and round area are easily 

 observed with the naked eye, but the band-like area is much 



