2130 The Zoologist— May, J 870. 



lalher deeper grayish ash, the colour extending a little further, and 

 more abruptly defined against the white of the other under parts. 



No vestige of a horn at base of upper mandible ; this being covered 

 with a soft skin, overlapping the culmen, extending to the nostrils, 

 which open beneath its lower border. That part of the bill occupied 

 by the membrane is depressed below the level of the rest, both on the 

 ridge and sides. The membrane is shrunken and shrivelled in its 

 present state. There appears to have been a slight tumidity, in the 

 fresh state, of this membrane, just on the ridge, which may have 

 elevated it to the level of the rest of the culmen, and which could 

 possibly even have been inadvertently called a " knob " by one who 

 regarded it as the beginning of a horn. No trace of an intercalated 

 piece between the mandibular rami, which have thin, sharp, smooth 

 edges, and come together in a fine point at the symphysis. liill much 

 smaller, weaker, and particularly less deep at the base than that of 

 C. monocerata ; but not much shorter, nor comparatively even so 

 much compressed as in the latter bird. Culmen regularly decurved 

 from base to tip; the latter moderately overhanging; rictus at first 

 nearly straight, then gently declinate ; gonys nearly straight, slightly 

 concave ; outline of mandibular rami about straight. 



Decidedly smaller than monocerata ; the wing comparatively 

 longer. Length about 1400; "extent 25-50" (label); wing 7-25; 

 tarsus riO; middle toe and claw 190, outer do. ISO, inner do. 

 r4o; bill — chord of culmen ISO, of which the membranous part 

 is '30 ; rictus r85 ; gonys "75; depth of bill at base 'CO ; its width 

 at same point '45. 



Young : " Membrane at base of upper mandible grayish dusky black ; 

 middle of both mandibles dingy orange, their tips dusky ; iris pale 

 hazel; under surface of the webs of the feet, and the posterior aspect 

 of the tarsi dusky black ; upper surface of the toes bluish white, darker 

 about the articulations ; nails black." (Suckley, 1. c). 



Much smaller than the adult; length "about 12-50; extent 24-00 " 

 (Suckley, 1. c.) : wing 650; tarsi 100; tail 200; tarsi 100; bill 

 along culmen r20, of which the membranous portion is '30; along 

 rictus rCO; along gonys -60; its depth at base "40. The VmII is small 

 and slender ; its general shape calls to mind the bill of a young gull 

 of one of the smaller species. The several outlines, particularly that 

 of the culuien, are slraighter than in the adult ; the tip is less decurved. 

 The bill is much longer, relatively and absolutely, than that of the 

 corresponding age of monocerata ; it is comparatively more slender. 



