Australian Birds in the Collection of the Linnean Society. 267 
which it is designed to break. In speaking of the shortness of 
this member, we measure the space between the rictus:and the 
apex, which in the birds to which we allude seldom equals the 
distance between the mentum and the same point. On the 
other hand, the remaining three subdivisions of the family have 
a longer, and consequently a weaker bill. The under mandible 
in particular becomes conspicuously elongated, the tomia or 
cutting edges being sometimes nearly straight, and the depth 
not equalling half the length. The bill thus assumes the gene- 
ral form which is found among birds, and deviates from that 
which appears peculiar* to this family. In some of these longer- 
billed birds, which we are thus inclined to consider aberrant 
among the Parrots, we shall have occasion to observe a devia- 
tion also from the mode of feeding prevalent in the family by 
the tongue partially superseding the use of the bill. Here we 
may trace the first approach to the Picide, Certhiade, and the 
honey-feeding. demuiragines zu birds which form a conterminous 
pum — c—(— 
and of which diets use of the tongue is the predominant cha- 
racter. 
According to these views we shall mane the shorter- and 
* We know no other bird in which this peculiar construction is found, except the 
Fratercula Arctica, Briss., in which species the depth of the bill from the front to the 
mentum is nearly equal to the length from the rictus to the apex. -This analogical re- 
semblance has given that bird the familiar name of Sea-Parrot. In some of the 
Loviade also we see an approach to the same depth and shortness of bill, but not an 
equal developement of the character. And here also the name of Psittarostra, attached 
to one of the groups, indicates the same analogy. We may observe, that the food of the 
birds of this latter family is similar to that of the Parrots, and requires corresponding 
powers of bill. When we speak of the height of the bills among birds, we do not take 
into account those eminences Which surmount the bills of some of the Buceride. 
These give an apparent rather than a real elevation to these members, and in no wise 
increase their strength. 
2m 2 stronger- 
