Annals of the Transvaal Museum 
85 
The length of the right pubis is in mm. Its breadth at the downward 
fold is 27 mm. The narrowest part of the pubic plate, which is near its distal 
end, measures 17 mm., while the breadth of the distal end is 20 mm. The 
lateral border of the pubic plate is thick and its medial border is paper thin. 
The right pubis does not show the thickening of the distal end, but in the 
left one it is clearly visible. The whole lateral border of the pubis is concave. 
The medial border is straight. The upper surface of the pubic plate is concave, 
at least near its proximal end. The left pubis shows plainly that lower 
surface of the pubic plate is convex. The 
proximal medial corner of the pubic plate is 
bent downwards and at right angles to the 
larger portion of the bone. The angle is 
rounded. The pubic neck continues from the 
proximal lateral corner of the pubic plate to 
the articulatio ileo-pubica. The narrowest 
place of the pubic neck has a breadth of 
11 mm. in the right pubis and a breadth of 
10 mm. in the left one. It is situated at 
22 mm. and 18 mm. from the articulatio 
ileo-pubica in the right and left pubis respec- 
tively. There is not much twist left in the 
neck of the right pubis, through the crushing 
of the bone. Its upper portion, however, 
still makes a considerable angle with the 
pubic plate. The medial side of the neck of 
the left pubis bends down more and more as 
it approaches the proximal end of the bone. 
The upper surface of the proximal end finally 
makes an angle of about 45 0 with the upper 
surface of the pubic plate. The upper border 
of the processus subacetabularis makes an 
angle of slightly less than 90° with the lateral 
border of the pubis. The breadth of the pubis 
across the processus subacetabularis is 25 mm. 
The height of the processus subacetabularis 
is much less at its lower than at its upper 
end. At its lower end the processus subace- 
tabularis is bent hooklike at an angle of 
about 90° in the direction of the distal end 
of the bone. The termination of the lower 
end is not abrupt; the upper border of the Fig. 4. Aristosaurus erectus. Upper 
processus subacetabularis rounds off gradually anterior view of right pubis, 
into the lower border of the hooklike process. About nat. size. 
Continuing distally, this process bends gradually more and more to the 
medial side, until it unites with the extreme end of the bent down proximal 
medial corner of the pubic plate. The breadth of this process at its middle is 
between 2 and 3 mm. Nothing is visible of the upper surfaces of the proximal 
end of the pubis. The neck of the pubis, the processus subacetabularis, the 
hooklike process and the proximal end of the pubic plate surround a large 
pubic foramen. It is situated nearest to the lower border of the proximal end. 
Its shape differs slightly in the two bones. In both it is elongated, and has 
a broad upper end. In the right pubis the lower end of the foramen is sharply 
pointed and the whole foramen pear-shaped; the upper end of this pear lies 
