ADDENDA TO THE INTRODUCTION. 
Humboldt’s Ara9ari belongs to section E, where it will range between Pter. viridis and 
Pter. inscriptus] as, 
Pter. Humboldtii ; with the bill yellow, black on its culmen at its tip and base, blotched 
with black at its serratures, and with the under mandible black. 
LangsdorfF’s, Natterer’s, and Reinwardt’s Ara9aris belong to section F, with the following 
distinctive characters; 
Pter. Nattereri ; with the bill red, marked at the base of each mandible with a large black 
spot, and having the culmen and five or six blotches along the edge of the upper 
mandible also black. 
Pter. Reinwardtii j with the bill reddish at the base, witli several black spots near the 
cutting edge of the upper mandible, and with the culmen and terminal half blackish 
brown. 
Pter. Langsdorffii^ with the bill throughout nearly black, becoming slightly grey towards 
its base. 
Pter. pavoninus, Derbianus, and hcematopygus will range in the seventh or last section, G, 
and are thus characterized ; 
Pter, pavoninus ; with the under tail-coverts and tips of the tail-feathers brown, and the 
lower mandible and base and cutting edge of the upper black. 
Pter. Derbianus ; with the under surface green throughout, and the tips of the two inter¬ 
mediate tail-feathers chestnut. 
Pter. hcematopygus \ with the under surface green throughout, and the upper tail-coverts 
blood red. 
As all the species comprised in this latter section appear to possess characters sufficiently 
distinct to warrant their separation as a peculiar genus, I propose to regard them in that light, 
and to give them the generic title of Aulacorhynclms, with the following characters : 
Bill comparatively short, furrowed on the sides ; culmen broad and flattened ; base of the 
under mandible extending obliquely beyond the line of the eye. Wings short and round, the 
fourth quill-feather the longest, the fifth, sixth, and seventh being nearly of the same length. 
Tail comparatively short and less decidedly graduated than in Pteroglossus. —^The whole of this 
group are characterized by a uniform green plumage, the feathers of which are loose and de¬ 
composed in their texture. 
