27



narrows towards the hardened apex it is crossed by a broad

blackish belt; the tip is horn-yellow; and the culmen towards the

tip bears a little conical prominence which renders the end of

the upper mandible obliquely truncate when viewed in profile.


The lower mandible seen from below is liorn-yellowish,

partly bordered and traversed just before the tip (which is

deflexed) b3^ a broad blackish ^-shaped band.


The most curious part of the mouth - ornamentation

consists in the character of what Dr. Russ calls the waxy-glands

(the expansions and warts at the posterior edge of the upper

mandible and at the back of the opening). The lateral expansion

is indeed not remarkable, being less developed than in many

species and of a pale milky yellowish tint ; but at the back of

the mouth are three prominent rounded tubercles in the form of

a triangle, two at the base of the mandibles of a bright and

almost metallic glistening opaline blue and one behind these of

a pale yellow tint.


The inside of the mouth is either ivory-white or flesh-pink,

the palate conspicuously marked (like a domino) with five more

or less round black spots in pentagonal form ; one in front, two

wide apart in the centre, and two near together at the back;

and, in front of each of the four posterior ones, an obliqire rosy

longitudinal streak (probably arteries, and owing their colour to

blood) ; the inside of the upper mandible is marked by a broad

^y-like baud each ramus of which is pterygoid ; very broad

beyond the middle, then abruptly narrowed and tapering to a

point.


The tongue is crossed just in front of its centre by a broad

belt, or by two large pear-shaped black spots, with apex directed

forward. The lower mandible is bordered inside with black,

and behind this border is a submarginal black V-shaped band.

Altogether the ornamentation of the mouth in this young bird

is very remarkable.


My sou and I have carefully examined the metallic

tubercles under the microscope and find that they are filled with

dark brown pigment, the iridescent-colouring being produced,

as I anticipated, by fine reticulation of the outer surface: this

reticulation is clearly discernible under a high power. A

transverse section shows the metallic gloss on the convex

face of the tubercle with the mass of brown pigment behind it.



