MONOGRAPH OF THE PETRELS. 



feathers of the back and scapulars broadly bordered terminally with ashy-white, the 

 middle and greater wing-coverts similarly marked ; chin, throat, chest, centre of 

 breast, and under tail-coverts, plain white ; rest of the lower parts vermiculated and 

 irregularly barred with slaty-grey or plumbeous, this becoming uniform and somewhat 

 darker on the belly ; tail chiefly plain light brownish-grey. Wing, 9.88 inches ; tail, 

 3.95 ; culmen, 1.03 ; depth of bill at base, 0.46 ; tarsus, 1.37 ; middle toe with claw, 

 1.7 (Ridgw., Man. N. Amer. Birds, p. 68, 1887). 



242 



