LETTER OF SUBMITTAL. 
Department of Agriculture, 
Division of Entomology, 
Washington , D. (7., May 15, 1888. 
Sir: I have the honor to submit for publication Bulletin No. 19 of 
this Division, being an enumeration of the published synopses, cata- 
logues, and lists of North American insects; together with other infor- 
mation to assist the student of American Entomology. 
Respectfully, 
Hon. Norman J. Colman, 
Commissioner of Agriculture. 
C. V. Riley, 
Entomologist 
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dj. ms 
