X 
E. Hitchcock on Fossil Footmarks of the Connecticut Valley. 49 
the remarkable slab of Anomcepus intermedius already described 
in this paper, I found on that, also, evidence that in some cases 
the outer toe had four phalangeal impressions beside the heel 
bone. So far as the Anomcepus is concerned, then, I feel sure 
that we have in its phalangeal impressions the normal number 
and order in the feet of living birds. I was at once led to in- 
quire whether the same thing might not be true in respect to those 
thick toed Lithichnozoa which 1 have regarded as birds. I have 
found proof enough to satisfy myself that it is so, and that the 
reason the fact has been overlooked is that the penultimate and 
ultimate phalanges (omitting the a rarely made separate 
impressions. But occasionally I can see a faint line of demarca- 
tion between them. But I had frequently noticed that the length 
of the ultimate phalangeal impression on the outer toe (as a 
reference to the outlines of these tracks in the Jchnology will 
show) was as long as, and sometimes longer than, those which 
preceded it, whereas, so far as I have examined the osteology of 
birds’ feet, they decrease in length toward the extremity. I 
think that ag y two phalanges have been mistaken for one, 
in this part of t 
If these are mente conclusions they lead to important 
results. The first is, that if we strike off the posterior impres- 
sion of the outer toe in the thick-toed bird tracks referred to, 
we shall still have the normal number of phalanges in the feet 
of living birds. But the same thing is proved still more de- 
cidedly i in regard to the Anomcepus, which is four-footed. Hence 
the conclusion —— that in the fossil footmarks birds cannot 
be a fro m quadrupeds by the number = temas 
seer results, + examinations have been confined vhiefly to 
the feet of birds, and the following facts have been obtained. 
The most important question under isaniderition 3 is this:—Is it 
the —e or the articulations of the toes that make the 
deepest impression on mud or other plastic material trod upon? 
This will be ewer by finding under which of these parts 
the protuberances are the most prominent. If under the pha- 
langes, the number in the toe will be one less than if under the 
articulations; that is, if we count, as one of them, the articulation 
with the tarsal or tarso-metatarsal bone. 
Am. Jour. — Series, Vou. XXXVI, No. 106.—Juxy, 1863. 
