SURF SCOTER. 



487 



From the carpal joint to the end of the whig, nine inches 

 and a quarter ; the lirst and second primary quill-feathers 

 of equal length, and the longest in the wing. 



The female differs from the male in having the plumage 

 of dull brown, which is lightest in colour about the cheeks 

 and under surface of the body ; the beak dark olive ; the 

 feet greyish-brown. 



There is considerable individual variation in this Scoter, 

 and some examples from California have been distinguished 

 as G^demia {Pelionetta) perspicillata trowhridgii. 



It has been stated that the trachea of the Surf Scoter 

 resembles that of the Velvet Scoter, but Mr. Herbert 

 Langton, in 'The Zoologist' for 1881, p. 59, points out 

 some differences. An illustration is given by Thompson in 

 the ' Annals of Natural History,' xviii. p. 370. 



The vignette below represents the difference in the extent 

 of the membrane depending from the hind toe of the two 

 divisions of true Ducks : that on the left side belongs to the 

 first division, or Surface-feeding Ducks ; that on the right 

 to the second division, the Diving Ducks. 



