MR. W. K. PARKER ON THE OSTEOLOGY OF BAL^NICEPS 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 ihum projects behind the ischium. In certain 

 birds — e. jr. 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 Balseniceps 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 (PI. LXVII, fig. 3z7, 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 (PI. LXVI. fig. 1 ph) 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. (PI. LXVI. fig. 1, and PI. 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 Balaeniceps 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 



