SKUA. NATATORES. CATARACTES. 523 



tail. Legs blotched with yellow; front of the tarsus 

 scutellated, the back part reticulated with small pointed 

 conical scales, giving it a roughness to the feel. Both 

 sexes are alike. 



PLATE 101. The bird of the year, in the natural size; from 

 a specimen obtained on the coast of Northumberland. 



Head and neck clove-brown, with striae of pale yellowish- Young, 

 brown ; most conspicuous upon the ear-coverts and hind 

 part of the neck. Back, wing-coverts, and scapulars, 

 deep clove-brown ; the feathers being tipped with yel- 

 lowish-white, inclining upon the ridges of the wings to 

 yellowish-brown. Quills brownish-black, with the lower 

 part of the inner webs and shafts white. Tail the 

 same ; the two middle feathers about half an inch longer 

 than the rest, and sharp pointed. Under plumage pale 

 clove-brown, undulated with yellowish- white and pale 

 wood-brown. Legs having the posterior part of the 

 webs and toes yellowish-white, the front part and claws 

 black. 



In this, and a still farther advanced state, it answers to 

 the Black-toed Gull of our authors. 



GENUS PROCELLARIA, LINN. PETREL. 



GENERIC CHARACTERS. 



BILL strong, straight, thick, subcylindrical ; the upper 

 mandible broader than deep at the base ; tip distinct, com- 

 pressed, arched, and hooked ; lower mandible laterally fur- 

 rowed, with a distinct, semi-truncate, and angulated tip, 

 much compressed, and fitting into the hooked dertrum of 

 the upper mandible. Tomia of both mandibles sharp ; those 

 of the upper slightly overlapping the under ones. Nostrils 



