THE WEIGHT AND LENGTH OF OTTERS 139 



pounder was the heaviest he has ever set up, but that Its 

 length, 49 inches, was exceeded by a 28-pounder killed by 

 the Carlisle hounds in the Liddle in June 1897, whose length 

 was 5 I inches. 



Messrs. Williams and Sons, the well-known Dublin taxi- 

 dermists, inform me that they do not think they have had any 

 Otters of over 28 lb. through their hands, but that the largest 

 measured 50 inches in the flesh. 



Lansdowne House, Lancaster. 



NOTES ON THE SEASONAL CHANGE IN THE 

 PLUMAGE OF THE GREAT NORTHERN 

 DIVER {COLYMBUS GLACIALIS). 



By F. W. Smalley, M.B.O.U. 

 Plate IIL 



Considering how meagre is the knowledge at present to 

 hand concerning the changes of plumage which take place 

 in our sea birds during the year, I feel that the following 

 observations of the changes as noted by me in the spring 

 moult of the Great Northern Diver may tend to throw some 

 small ray of light on this very interesting matter. 



Before proceeding farther I must make it clear that I 

 am dealing entirely with the change of fully adult birds 

 from their winter to their summer plumage, and although I 

 mention the differences between adult birds and birds in 

 their first winter plumage, I merely do so in order to enable 

 others to clearly distinguish between young and old birds 

 when checking my observations with any skins of Colymbus 

 glacialis which they may come across or possess in their own 

 collections. 



Reference to the published plate of feathers will from 

 time to time be necessary as indicated in the text. 



The full adult winter plumage of the Great Northern 

 Diver is a simple one, and the plumage of both sexes is alike 

 in both winter and summer feather. 



