2A.2 Goss on Birds of San Pedro Martir Isle. I July 



tire lower parts, including flanks, axilhiries, and most of the under wing- 

 coverts, pure white, broken only on the sides of the lower neck by rather 

 indistinct broad streaks of pale sooty grayish, changing posteriorly next 

 to back into more distinct spots of a deeper hue; feathers of back and 

 scapulars deep sooty grayish or grayish brown, rather broadly but not 

 abruptly tipped with dull white, these terminal spots larger and more dis- 

 tinct on posterior scapulars; wing-coverts entirely plain grayish brown 

 or light sepia, deepening gradually into sooty slate on primaries ; lower 

 back and lower rump pale grayish sepia, fading gradually into white on 

 upper tail-coverts; the upper parts of rump chiefly pure white ; middle 

 tail-feathers white, faintly shaded on outer portion of outer web for about 

 the terminal third with pale brownish gray, their shafts entirely clear yel- 

 lowish white, the outer pair wholly sooty grayish (darker terminally and 

 on most of outer web), the others gradually paler towards the middle 

 pair. 



Adult female. — Essentially like the male, but differing in the following 

 particulars : Iris paler yellow, plumage somewhat darker, except the hind 

 neck, Avhich is less distinctly streaked, and size larger. 



The following measurements are from specimens saved, the first two are 

 in the Goss Ornithological Collection, the last two in the National Mu- 



The birds make no nests and lay but one c^^ ; this they drop 

 upon the smooth rock, often in exposed situations, preferring the 

 phices where the guano had been removed and, in many cases, 

 close beside the winding paths that were hourly trodden. I found 

 no young birds, and from the condition of the many eggs examined, 

 think they do not commence laying before the ist of March. 

 Average measurement of 3i eggs, 2.42 X 1.60; ground color 

 greenish blue, coated with a dull white chalky substance, but 

 generally more or less stained with the guano that gives them a 

 dirty buft' white look ; in form elliptical ovate. 



Sula brewsteri,* sp. nov. Brewster's Booby. 



Sp. Char. — Similar to 5'. sula, but mantle ending uniform in color with 

 head and neck, the last two paler, especially in the male, in which the 

 neck is pale drab gray fading into white on anterior portions of head ; un- 



*To my esteemed friend, William Brewster, Cambridge, Mass. 



