Prof. Huxley on Archeopteryx lithographica. 221 
poses, the right leg, it would obviously be impossible to place the 
foot in its present position, unless the numbers of the phalanges in its 
toes were the reverse of what is observed in Birds; that is to say, the 
uppermost toe, that which has three phalanges, must also be the 
outermost. Nevertheless the describer of the fossil justly lays great 
stress upon the fact that the toes have the same number of phalanges 
as in birds. As a matter of fact, this is quite true; but it would 
not be true if we were to assume with him that the limb in question 
is the right leg. | 
3. Certain parts of the fossil which lie upon the opposite side of 
the spine to the so-called “right leg” are named, at p. 34 of the 
memoir cited, “ Portion of the left os innominatum, showing part of 
the ilium (62) and ischium (63), with the acetabulum (a).” 
A full description of this mass of bone as “ the left os innomina- 
tum, including the anterior two-thirds of the ilium, and the anterior 
half, or more, of the coalesced ischium,”’ is given at p. 39; and at 
p- 40 I find, “‘ The inferior or central* face [of the sacrum], as in 
the case of the slightly dislocated left innominatum,.is towards the 
observer.” 
There is no doubt on any side, that the end of the bone in question 
which at present is directed forwards is its true anterior end, and 
that the edge which is turned towards the spinal column is the true 
dorsal edge. The question is, whether the face of the bone which is 
exposed is its outer (or dorsal) or its inner (or ventral) face. In the 
former case it must needs be a right ilium, in the latter a left 
ilium. 
That it is the outer face of the bone which lies uppermost appears 
to me to be demonstrated— 
(a) By the fact that the iliac margin of the acetabulum is promi- 
nent, and that the adjacent surface of this ilium rises to this margin. 
I am not aware that any vertebrate animal exists in which the ace- 
tabulum lies at the bottom of a funnel-shaped depression, such as 
would be the case in Archeopteryz if the bone in dispute were the 
left os innominatum seen from the inner side. 
(6) By the fact that a small portion of what appears to be an inno- 
minate bone can be descried in close relation with the proximal end 
of what has just been shown to be the left femur; while the right 
femur (called left in the memoir), though dislocated, is not very far 
from the bone under discussion. 
(ec) By the further consideration, that if this were not the right 
os innominatum, it would be as curiously unlike the corresponding 
bone of a bird in the form of its surface as it resembles it in all other 
respects. 
4. The bone marked 51’ is named “left scapula” (¢. c. p. 34), 
and that marked 51 ‘right scapula”’ (J. e. p. 35); and a full de- 
scription of these bones, as such, is given at pp. 36 and 37 of the 
memoir cited. 
* “Central” in the original. The word appears to have been substituted 
by an error of the press for “ ventral.” 
Ann. & Mag. N. Hist. Ser. 4. Vol. i, 16 
