NATURAL SCIENCES OF PHILADELPHIA. 37 



Bucephala americana. (= B. dangula ?) 

 Bucephala albeola. 

 Fulix marila. 

 Fulix affinis. 

 Aythya americana. 



Of these the two last named are apparently the most abundant. 

 The canvas-back I have never seen here. 



Oedemia perspicillata. 



Yery common. Early in November, 1870, before the comple- 

 ment of general wild-fowl was made up, these were perhaps the 

 most abundant ducks on the harbor, mixed with a number of the 

 next species. By far the larger proportion were females and 

 young. The young males at this season almost exactly resemble 

 the females ; having the two Avhitish spots on each side of the 

 head, and bill wholly black, the place of the future black spot in 

 the bill being indicated b}^ a slight corrugation of the skin. But 

 they are generally distinguishable by the presence of a few per- 

 fectl}^ black feathers about the head, and by the rather more 

 turgid bill. 



Oedemia americana. 



Common. The female and young are distinguished from those 

 of the last by the different number of tail-feathers, different shape 

 of bill, and the continuously whitish sides of the head ; other- 

 wise the resemblance is very close. Both are known as " black 

 ducks," and by a probable further confounding with A. ohscura, 

 are pronounced good eating by those who do not intend to eat 

 them. 



Mergus serrator. 



Very abundant. I should judge this to be the most numerous 

 of all the family in this vicinity. They are alwa3's on the harbor 

 from October to April, and a few both earlier and later ; and are 

 not much molested, being unacceptable even to not over-fasti- 

 dious people. The distribution of their colors, showing large pure 

 white areas, marks them out at any distance ; the Bucephala^ 

 being the only ducks to which thej^ bear any special resemblance. 



Pelecanus fuscus. 



A few observed at irregular intervals through the summer 

 months. 



1871.] 



