336 Shooting of Cygnus Bewickii. By Thomas Anderson. 



flew from one end to the other twice before it was shot. 



Both specimens were preserved and a description with carefully 

 noted measurements taken as follows. 

 A. From larger specimen. 



1. From tip of bill to tip of tail, 49^ inches. 



2. Length between tip of each wing, 83f inches. 



3. ,, wing from carpal flexure to tip of longest primary, 

 22f inches. 



4. Bill along upper outline, 4 inches. 



5. Tarsus, 4^ inches. 



6. Middle toe, 5^ inches, 



7. Claw of middle toe, finch. 



Primaries ten, second and third longest and of equal length. 

 Tail twenty. Iris brown. Legs, toes, and webs black. Bill 

 black, but at base the covering skin a brilliant chrome yellow, 

 which colour reached to half way between base of bill and 

 nostril. 



Entire plumage snowy white. 



But it is in the structure of the trachea and sternum that the 

 characteristic features are met with, the keel of the latter being 

 modified in a remarkable manner to receive a peculiar develope- 

 ment in the former. 



The sternum is neither so large nor so strong as might be 

 expected in a bird of such a size. Its extreme length is 7i-6 

 inches, and its greatest width, which is across the plate just 

 behind the point at which the keel springs, is 3|- inches. Though 

 of comjjaratively thin construction, its surface is well marked by 

 the rough lines of attachment of the great pectoral muscles, which 

 run in well defined ridges along the plate and the sides of the 

 keel. On its posterior edge it has the two deep notches char- 

 acteristic of the Anseres which run up to a depth of l-re inches. 



It is in the keel itself that the remarkable modification referred 

 to is met with. Commencing posteriorly in a smooth triangular 

 surface, 1^ inches ^from the posterior edge of the sternum, the 

 keel gradually rises and runs forward for 5^ inches, attaining 

 its greatest depth, 5J inches, at its anterior extemity. The 

 smooth surface does not run into a narrow edge as is the case in 

 most birds, but presents inferiorly a flat surface throughout its 

 entire length. In front this surface is i inch wide, it contracts 

 about the middle to f inch and expands again to | inch posteriorly^ 

 where it first rises from the plane surface of the sternum and 



