[ Table- 
case 1n 
window 
of Bay. ] 
[Cases 
31, 32.] 
56 BIRD GALLERY. 
this pouch is retained in adult birds throughout the year or developed 
afresh each season. A female of the Great Bustard with her downy 
nestlings may be seen on the floor of Case 29. 
The largest of all is the Paauw or Kori Bustard (Hupodotis kori) (892), 
from the plains of Africa; and among the forms characterised by orna- 
mental plumes on the crown and neck we may draw attention to 
Macqueen’s Bustard already mentioned above, and the Lesser Florican 
or Likh (Sypheotis aurita) (588), which is further remarkable for its 
acuminate flight-feathers. 
Order XIII. OPISTHOCOMIFORMES. 
Family Opisrnocomip#. Hoarzin. (Plate X.) 
The singular South American bird known as the Hoatzin (Opistho- 
comus hoazin) (594) is the only representative of this Order, and has 
been referred by different naturalists to the Game-Birds and other 
groups. In spite of its external resemblance to the Guans, it is perhaps 
more nearly allied to the Rails, while certain points of structure seem 
to indicate considerable affinity to the Cuckoos. It inhabits the banks 
of the Amazon and other great South American rivers, extending as far 
south as Bolivia. The skeleton presents many remarkable modifications, 
the sternum being unlike that of any other species of bird. The keel 
is much reduced and its posterior termination is flattened-out into a 
broadened surface which supports the greater part of the weight of 
the body when the bird is at rest. The enormous size of the crop has 
probably caused the curious modifications which the furcula, sternum, 
and pectoral muscles have undergone. ‘The food consists of leaves and 
fruit, and the birds after death have a very unpleasant odour which 
prevents them being used as food. In spite of their large wings the 
flight of these birds is very feeble and awkward, and when disturbed they 
only fly for a very short distance. 'The nestlings, which can both see 
and crawl soon after they are hatched, have a well-developed claw on 
the pollex and index fingers of the wings by means of which they-creep 
about among the branches assisted by the bill and feet. They can also 
swim and dive well. The nest, a loose platform of spiny twigs, is 
placed on branches overhanging the water, and the eggs closely resemble 
those laid by the Corn-Crake and other Rails. 
Order XIV. GRUIFORMES. Crane-tiket Birps. 
This Order includes the Cranes and a number of allied but some- 
what aberrant forms. In general external appearance they resemble 
