WORK IN THE UNITED STATES 
5 
lection. (A more detailed account of the whole transaction will he 
found in Part II, Chapter XII.) 
This is not all. During my long residence in the United States 
I had formed a collection of Diptera for my own use. It con¬ 
tained : — 
(1) All the types of the new species described in my own mono¬ 
graphs, and in my other papers of this period ( Tipulidae brevipalpi, 
Tabanidae, Cecidomyiidae , Western Diptera , etc.). 
(2) Numerous duplicates, many of them numbered , of the spe¬ 
cies I had sent to Loew for the purpose of having them described. 
Such specimens, not having crossed the ocean twice, and not having 
been so much handled as the typical specimens of the collection in 
Loew’s hands, were for these reasons in a much better state of 
preservation. Of this my own collection I made a present to the 
same Museum in Cambridge, Mass., as a token of my gratitude to 
Professor Agassiz for his generous assistance in the realization 
of my principal scheme. During the two winters which I spent 
in Cambridge, Mass. (1873-1875), I incorporated in this collection 
the dipterological materials accumulated in the Museum before 
1873, principally by Mr. P. R. Uhler, and thus formed a collec¬ 
tion which is now kept separate from the other collection, and 
which affords a useful supplement to it. 1 A considerable collec¬ 
tion which I had formed of deformations of plants (as galls of 
Cynipidae, Cecidomyiidae, Trypetidae, etc.), fungoid excrescences, 
and also vegetable hypertrophies, was included in this gift. 
Thus far, for clearness’ sake, I have anticipated events, and now 
I return to June, 1856 (the date of my landing in New York), for 
the purpose of giving a more circumstantial account of my share 
in the common work, between Loew and myself, on the dipterous 
fauna of North America. My first task was the compilation of a 
Catalogue of all the previously described species of the Diptera of 
North America. It was accepted for publication by the Smith¬ 
sonian Institution, and was the third of the long series of entomo¬ 
logical works since published by that Institution (compare my 
“List,” 4, 1858). 
1 On this collection I made a detailed Report to the Trustees of the Museum. Com¬ 
pare 44 (1875) of my “List.” 
