MR. W. K. PARKER ON THE OSTEOLOGY OF BALANICEPS REX. 337 
margin also of this bone (the ischium) is sharp, but it becomes thicker beneath the 
ischiadic foramen, the sharp inferior ridge first passing obliquely upwards to form the 
anterior margin of that foramen; and then the rest of the anterior part of the ischium 
is round below, convex within, and concave externally. The posterior end of the ischium 
is thin, incurved, and nearly touches the pubis, which reaches half an inch further 
backwards. That part of the ischium which, having coalesced with the ilium, passes 
downwards and a little outwards, is moderately thick, and is half an inch deep. The 
ischium passes obliquely backwards eight or nine lines further than the ilium ; in this 
it resembles the Heron ; in the White Stork it terminates in the same vertical line, 
but in the Adjutant and Boat-bill the ilium projects behind the ischium. In certain 
birds—e. g.the Fowl—a short but strong process projects forwards where the ilium joins 
the pubis beneath and rather in front of the acetabulum. In the Baleeniceps and its 
congeners, the Herons and Boat-bills, as well as in the Storks, this spur is absent ; yet 
the os pubis is very thick, rounded, and smooth at this part (Pl. LX VII, fig. 371, ach), 
but soon becomes thin and flat more posteriorly, where it is distinct from the mass of 
bone forming the lower part of the acetabulum. Its width is at first two lines, gra- 
dually expanding to more than three, two inches further on; it then contracts a little 
for half an inch, widens again, and then rapidly runs to a point as it curves inward 
to form its tip. This bone is of unusual width (Pl. LXVI. fig. 1 pb) twice as wide as 
in the large Indian Adjutant ; but it has all the essential characters of the same bone in 
its congeners. This os pubis is flat externally, at first convex and ridged within, and 
then at its widest part slightly concave. The distance between the pubic bones is at 
first two inches, then at their widest part, which is in the same vertical line as the tips 
of the ilia, they have divaricated seven lines more. They now make an elegant curve 
inwards, below and a little external to the ischia, and their tips are but one inch and 
two lines apart. Seen from above, the curving inwards of the ilia, ischia, and ossa pubis 
is a very beautiful structure. Opposite the widest part of the ischiatic foramen, the 
pubis is four lines apart from the ischium ; it gradually nears that bone, and they almost 
touch behind. An interosseous membrane perfects the great obturator foramen, here 
two inches and three-quarters in length. 
Sternal Apparatus. (Pl. LXVI. fig. 1, and Pl. LXVII. fig. 1.) 
The scapula, coracoid, and sternum, in this bird, are relatively stronger than in the 
Herons, being quite equal, in proportion to the size of the bird, to what they are in the 
Adjutant. A few comparisons will make this evident ; the measurements are in inches 
and lines. 
The scapula (PI. LXVI. fig. 1 sc) is a very exact counterpart of that of the Adjutant, 
and so is the coracoid except at its head, which is more than an inch and a half broad 
in the great Indian bird, whilst in the Baleniceps this part has only half that breadth. 
There is also in the latter bird a flat oval articular surface in front of the head of the 
