1869] ss SENATE—No. 60. 85 
harmonious representation of the animal kingdom during the 
Tertiary age, —so disposed as to stand in becoming relation to 
the forms of an earlier day, no less than to those of the existing 
era, — with all the parts in such a way designated, as to give 
due credit to every previous collector, observer, and collaborator 
in this broad field of inquiry. 
» It was consequently natural for me to feel, in undertaking the 
‘systematic arrangement of the Tertiary fossils of the Museum, 
that I had a great task before me. I accordingly began at once 
to prepare for it by a more thorough study than had before been 
in my power, of the several branches of the animal kingdom, 
and especially by a more exhaustive and minute investigation 
of the Tertiary, as well in all the manifold phases embraced in 
itself, as in its relations alike to the past and to the present. 
Entering immediately upon the practical work to be done in the 
Museum, I found myself in due time separating all the zodlog- 
ical remains of the Cainozoic age into grand groups or parcels, 
according to the several branches and classes to which they 
respectively belong. At the suggestion of the Director, I took 
‘up, at the very start, the Pleurotoma, a group of Gasteropods, 
as a special study. Bringing this group of fossils together by 
slow degrees, and devoting myself to a minute investigation of 
them as they appear in a fossil state, and in their relations to 
their living representatives, I gradually from this group as a 
centre, worked my way outward in different directions, as occa- 
sion offered. Advancing in this manner, I proceeded to sepa- 
rate the entire assemblage of tertiary Gasteropods into kindred 
groups of about the same equivalence, as Murex, Fusus, Ceri- 
thium, and the like, according to their zodlogical affinities. This 
work has been diligently prosecuted, and is largely accom- 
plished. | 
In addition to this, I have also been over these several differ- 
ent groups, one after another, aiming to bring together in small 
specific circles, all the individuals in each larger section, accord- 
ing to their specific affinities. Having done this roughly for the 
entire division of Gasteropodous Mollusks, I have in several 
large groups taken up every specimen, examined it closely, and 
thus endeavored by critical study, to bring into its appropriate 
specific circle, each individual according to its natural and 
characteristic features, as indicated by the object itself. This 
