E. Hitchcock on Fossil Footmarks of the Connecticut Valley. 47 
and photographs, and, should the Society ae it, these I think 
will fully sustain the conclusions at which I have arrived. 
The collection of Footmarks at the College, whose examina- 
tion has led to the following unexpected conclusions, is now 
quite large. I have counted the number of individual tracks 
them are the tracks of insects and small crustaceans. It was, 
however, some of the specimens in the collection purchased the 
past winter, by the generous contributions of the friends of sci- 
ence, that first opened my eyes to the facts detailed below. 
Supposed Mistake as to the number of Phalanges in some of the 
Lnthichnozoa.—It is well known that the number of phalanges 
and their order, in the toes of living birds, enable the anatomist 
- to distinguish them from other animals, with only a few ex- 
ceptional cases. In four-toed birds it is two in the inner toe, 
three in the second, four in the third, and five in the outer toe, 
and where there are only three toes, the numbers are the same 
as in the three outer toes of the four-toed birds. But since the 
penultimate and ungual phalanges would make only one im- 
het we should expect in the track that the numbers would 
e one less than above indicated. And such they seemed to be 
to every observer without exception in the three-toed pachydac- 
tylous Lithichnozoa, viz: two in the inner toe, three in the 
middle and four in the outer toe. This of course was regarded 
as the grand argument to prove them made by birds. 
For some time past my suspicions have been that we have all 
been mistaken as to the true number of phalanges, and when I 
went into an examination [ found it even so in respect to the 
_ outer toe. By looking at the drawings which myself and others 
__ have published of these tracks, it will be seen that what we have 
_ supposed the posterior phalanx, in that toe, lies wholly behind the 
_ first phalanx of the inner and middle toes, and sometimes also a 
little out of the line of the other parts of the toe. Now by looking 
Pp 
his fact, I confess, very much unsettled my conviction that 
any of the Lithichnozoa were birds. And they were still farther 
shaken by the facts I have already detailed respecting that most 
