Plate 55. 





% 



Great Black- Tracked CKiU . 



I ^ 4 





.1 





*+j',yS 



r 





jpty 



(rr-eat Black- Tracked Gull. 





Great Black.-liead.ed. GidL. 



Paws^r. 8c Bradsfori LitV Sheffiell 



