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Annals of the Transvaal Museum 
anterior angle is therein directed downwards, the upper horizontal border is 
the posterior side, while the long lateral side of the head lies on the right-hand 
side of the figure. If an upper view of our left ulna is placed alongside of this 
text-figure, it will be seen that while the anterior angle is directed downwards 
and the hinder border lies away from the reader, the longest border is situated 
on the left-hand side of the figure. However, if an upper view of the right ulna 
of our specimen be placed alongside of the upper view of the left ulna of 
Plateosaurus Quenstedti , it will be seen that the two figures are identical. 
Moreover, in an adjoining text-figure the lateral side is shown of the left ulna. 
This lateral side is identical with the medial side of our right ulna. These 
considerations would lead to the conclusion that, what is supposed to be the 
left ulna of Plateosaurus Quenstedti is really the right one. With the ulna of 
Plateosaurus erlenbergiensis v. Huene it is the same thing. What is described 
as the head of the left ulna corresponds with the head of our right one. What 
is called the right ulna of Pachysaurus ajax v. Huene on p. 143, l.c. would be 
the left one according to our specimen. 
From the above may be concluded that the shape of the head of the right 
ulna of Plateosaurus Reinigeri is not identical with the contour of any of the 
mentioned right ulnar heads; that it would be identical with the contour of 
the right ulnar head of our form if it were turned 90° on its axis; that the 
contour of the left ulnar heads of Plateosaurus Quenstedti, Plateosaurus erlen- 
bergiensis and Pachysaurus ajax is identical with that of the right side of 
our form. 
On p. 59 l. c. v. Huene gives a figure and a description of the left radius 
of Plateosaurus erlenbergiensis ; the figure presents a medial view. The anterior 
portion of the medial border of the proximal end and the posterior portion of 
its lateral border are shown to be high. A medial view of the left radius of 
our specimen shows the posterior part of the medial border and the anterior 
part of the lateral border to be high. The contour of a reflected image of the 
lateral side of our left radius is, however, identical with the contour of the 
medial side of the left radius of Plateosaurus erlenbergiensis ; or, in other words, 
the contour figure of the medial side of the left radius of Plateosaurus erlen- 
bergiensis is identical with the contour of a lateral view of our right radius. 
These considerations would therefore lead to the conclusion, that what is 
styled left radius of Plateosaurus erlenbergiensis is really the right one. 
Dr Broom gave a figure of the left ulna of M assospondylus Harriesi 
( 7 , PI. XVI, fig. 15) and it clearly shows that the long side of the triangular 
head lies medial, while the angle between the two short sides lies on the 
lateral side. This is therefore in full agreement with the ulnae in our specimen. 
I would like to point out that our specimen was taken out of the matrix 
by myself and that no interchanging of bones could have taken place. The 
left arm was out of the matrix and every bone labelled and packed away long 
before the right arm was discovered. Moreover, weathering agencies have had 
a different effect on the two arms, all the bones of the left arm now having 
a reddish colour, while all those of the right arm are white. Besides, the bones 
of the left arm have only suffered slightly from pressure, while nearly all the 
bones of the right arm are badly crushed. Therefore, even apart from my 
statement, there is every reason to believe that the bones did not get mixed up. 
I have given the measurements of the heads of the tibiae, because I would 
like to prove the folly of describing fragments in such a crushed and flattened 
condition under new generic and specific names. If the heads of the above 
described tibiae had been found separate one could never have proven them 
to belong to the same nor to different species. However, for example Euskele- 
