ANNALS OF THE QUEENSLAND MUSEUM, No. 6 41 
species, but no slenderer in the shaft ; the head and neck are con- 
siderably narrower, the tubercle for the loop of the biceps cruris, 
present in other Ibididw, appears in this species to be nearly 
obsolete, scarcely marked off from the outer condyle, but the median 
tubercle (Fig. 2 Ab), proximad of the popliteal space, is largely 
developed, and is followed distad by a sharply curved line partially 
enclosing a low eminence, an arrangement which does not appear 
to occur in other Australian members of the family. The foramen 
beneath the neck is minute. Locality, Wurdulumankula. 
This species is placed in the genus Ibis provisionally. It will 
probably not remain there when its structure is better known. 
FAMILY ANATID.E. 
To judge from the contents of the collection under study, 
Swans were among the more numerous of the birds that frequented 
the old lake ; next to the Cormorants they were the most 
numerous. Their bones are seventeen in number. There appear 
to have been two species — a rather dwarfish one, which can hardly 
be separated generically from the present black swan, and a portly 
one which has claims to be brought apart in a generic niche of its 
own. The bones which may be brought forward in support of 
its claim are these : the coracoid, humerus (two) — radius, and 
ulna of the wing ; the femur (two), tibia, and metatarsus of the 
leg. These it is proposed to notice under the name 
Arch^eocycnus lacustris n.g. and sp. 
Coracoid. — Distal half or less of the coracoid of the left side, 
minus the external angle of its base (Plate III., fig. 1 AB). The 
supracoracoideal surface {Ab,) is separated from that external 
to it by a longitudinal ridge, which is much more convex and 
pronounced than that in the Black Swan, Chenopis, and does not 
bear on its summit a raised limiting line of muscular attachment. 
The articulating surface for the groove of the sternum is more 
concave, and notwithstanding that it is a little imperfect at both 
ends, markedly greater in both its dimensions. The oblique 
ridges on the visceral surface of the bone are less regular and 
numerous, thinner, more sharply raised and less continuous. The 
breadth of the shaft at its point of fracture is sensibly the same 
as in C. atrata. Locality, Lower Cooper. 
So far as the structural characters of a coracoid allow one to 
judge, we may suppose this swan to have had a broader and deeper 
breast, itself indicating a larger body than the present one, but, 
perhaps, no greater power of wing. 
Humerus. — Two distal ends, a right and a left, of this bone 
(Plate III., fig. 2 A and B) are distinctly those of a swan, but un- 
luckily are not sufficiently perfect to afford us as much information 
as we could wish. They differ not a little in form from the recent 
