REPORT ON THE DEPARTMENT OF INSECTS IN THE U. S. NATIONAL 



MUSEUM, 1887. 



By C. V. Riley, Honorary Curator, 



The general work of the year was mainly that of arrangement, as by 

 far the greatest amount of time has been devoted to the separation of 

 material, and its more or less complete arrangement either for exhibi- 

 tion or study. 



First in order, the arrangement of the Lepidoptera from the Rhopalo- 

 cera to the end of the Arctiidce has been completed. This had been 

 begun during the preceding year and nearly completed. The work this 

 year embraced the addition of new material, the completion and partial 

 re-arrangement of series, and such changes as experience suggested. A 

 tolerably complete statement of this part of the work is contained in 

 last year's report, and nothing more need be said here on the same 

 subject. 



A more tedious, and in many respects more important, work was the 

 separation into families of the material in the order Diptera. 



There was in the order the material of the Burgess collection, much 

 of it without labels, and most all of it without arrangement of any kind; 

 the material in the Belfrage collection in somewhat similar condition; 

 the material of the Riley collection and that of the Department of 

 Agriculture containing a vast lot of bred species ; the Riley collection 

 being the only one with any attempt at arrangement. The work of Dr, 

 Williston, in the winter of 1885, on this collection included the separa- 

 tion and arrangement of some of the leading families, and these served 

 as a guide and basis for the continuation of the work. 



There are now 107 boxes of material arranged as to families, much of 

 it determined genetically or specifically; the boxes of all sizes, many of 

 them large, double storage cases. 



A series of eight unit boxes was prepared, containing a synoptic col- 

 lection of North American Coleoptera, with labels defining and draw- 

 ings illustrating the families of this order. A more detailed statement 

 of this work is given further on. 



The collection of Arachnidce has been overhauled, partly remounted, 

 and roughly separated for convenience of future study. The old ma- 

 terial in adolescent stages has been similarly treated. 



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