^PTEROGLOSSUS PRASINUS, Lichtenstein. 
Golden-green Ara^ari. 
Specific Character. 
Pter. mandibuld superiore Jiavd, culminis strigd, maculd ante nares, linedque ad tomium nigris ; 
ir^eriore nigrd,fascid basaliJiavd: supra aureo-viridis, in cceruleum ad remiges et ad rectrices 
extrorsum transiens, harim apicibus ritfo-brunneis; genis guldque cinereis; pectore coeru- 
lescenti-viridi, in viridem postice transeunie ; tectricibus caudce irjerioribus rijis. 
Juvenis. Mandibidd superiore ad basin rijo nebidosd versus apicem in Jlavum et lutescentem 
vergente ; irjeriore totd nigrd: abdomine qudm in adulto obscuriore. 
Upper mandible yellow with a black line along the culmen, a black spot before the nostrils, and 
a dash of the same colour along the edge; under mandible black with a basal border of 
yellow; upper surface golden green, passing into blue on the cjuills and lower half of the 
tail-feathers, which are tipped with rufous brown; naked skin round the eyes dull blueish 
green; cheeks and throat grey; breast blueish green, passing into green beneath ; lower 
tail-coverts rufous; tarsi lead colour. 
In the immature bird the abdomen is the same though less bright; but the upper mandible is 
clouded at its base with reddish, passing insensibly into yellow and greenish at the point; 
under mandible black. 
Total length, 13 inches; bill, 3. 
The naturalist has often to observe, that Nature never proceeds abruptly in the formation of her groups, but 
prepares a passage from one to another by a series of intervening gradations, embodying, though in a minor 
degree, the distinguishing characteristics of the two sections to which they form the connecting link: such is 
the case with the species before us. In my description of the Pteroglossris stdcatus, I hinted that at a future 
day it would in all probability constitute the type of a new genus; this division would be characterized by an 
attenuated and channelled bill, together with a more subdued and uniform style of colouring, and a short, 
graduated tail. To this form the Golden-green Arafari appears, at the first glance, to be related, and might 
with propriety be placed there in a strictly systematic arrangement; a more attentive examination, however, 
indicates its i-elationshlp, in an equal degree, to the more genuine Pteroglossi. The bill, for instance, though 
channelled, is only slightly so, and approaches that of the Aracaries in breadth and general dimensions ; and the 
tips of the tail-feathers and under tail-coverts, as in most of that genus, are rufous brown. 
The Ptei'oglossus prasinus is exceedingly rare; indeed, I know but of one museum in Europe possessing 
specimens, namely, that of Berlin ; and I am indebted to the kindness and liberality of Professor Lichtenstein, 
who first made It known to science, for permission to examine and make drawings of the unique examples 
under his immediate care,—a favour for which, among many others, I beg to express my warmest thanks, and 
at the same time acknowledge my obligations. 
Of the habits and oeconomy of the Golden-green Arafari, as distinguished in the minuter details from 
those of its race, I have no information to communicate; there is, however, one fact, as the Plate will show, 
sufficiently illustrated, namely, the change which the beak undergoes, not only in size, but also In colouring, 
during the progress of the bird from youth to maturity,—a change not peculiar to this species alone, but 
characteristic of the whole family ; and I may add, that it is from a want of sufficient attention to this clrcum- 
stanee, that many mistakes and much confusion have arisen. As regards the development of the beak, I may 
observe, that it is much more gradual than that of the rest of the body; for when the latter has acquired its 
complete dimensions, the former is little more than a third of the size it is afterwards to attain. 
Inhabits Mexico. 
