42 BIRDS OF OHIO. 



Its migrations cover the period from the second week in 

 March to the second week in April, and at the same period 

 in October and November, except that it may tarry even into 

 December in favorable years. 



38. (147.) AYTHYA VALLISNERIA (Wils.). 259. 



Canvas-back. 



Synonyms: JEthya vallisneria, Fuligula vallisneria, Anas val- 



lisneria. 



Canvas-back Duck. 

 Kirtland, Ohio, Geol. Surv., 1838, 166, 187. 



The delight of the epicure, and therefore hunted down by 

 every market hunter, this duck has become scarce. I have 

 seen it twice in Lorain county in the last ten years, once 

 when it visited the Oberlin water-works reservoir. 



It appears to migrate at the same time as the Redhead, 

 but migration dates are too few to make any positive state- 

 ments possible. 



39. (148.) AYTHYA MARILA Linn. 256. 



Greater Scaup Duck. 



Synonyms: Fulix marila, Fuligula marila, Aythya marila ne- 



arctica. 

 Greater Black-head, Big Black-head, Blue-bill, Broad-bill, 



Raft-duck, Flocking Fowl, Shuffler, American Scaup Duck. 

 Kirtland, Ohio Geol. Surv., 1838, 166, 187. 



In my experience this Scaup Duck is about one-fourth as 

 numerous as the Lesser Scaup ; that would make it hardly 

 common. There is often one or two of this species in the 

 flocks of Lesser Scaups which visit the Oberlin water- 

 works reservoir every year. There is no evidence that this 

 species breeds within the state. The birds which may be 

 found on the reservoirs during the summer, while they may 

 be of both sexes, are not breeding, but are no doubt wound- 

 ed birds unable to migrate. Their bodily condition would 

 make breeding out of the question. 



The migrations are rather late, occurring late in March or 

 early in April, and continuing for two or three weeks. In 



