PREFACE. 17 



the knowledge concerning the species; (4) the changes made in generic 

 location. Under this latter head I have not included references to such 

 lists as adopt a different generic term for an entire genus, e. #., Mr. 

 Grote uses Apatela and Helioplithi for Acronycta and Leucania-, but I 

 have not cited his lists for this change in term since it does not carry 

 with it any suggestion of difference in structure. Where a species ap- 

 pears in the catalogue in a genus different from the ore last cited, the 

 reference is usually to be credited as original here or in my list of the 

 Lepidoptera of boreal America, published in 1891. 



In synonyms the same rules are observed, because the literature of 

 the synonym is often better or more accessible than that of the original 

 species, and the final reference given is that which places the name as 

 a synonym. Usually I have given a reference only to the first positive 

 statement of the synonymy; but where more than one observer have 

 independently so referred a name, I have as a rule cited them all. 

 Where no reference to the synonymy appears in the bibliography it 

 is original here. 



Finally, while I have given the reference to the original descriptions 

 of the genera, I have not given generic synonyms nor references to re- 

 descriptions of a genus. The generic synonymy appears sufficiently in 

 the bibliography of the species, while redescriptions will be readily found 

 under the same references. I have made no attempt to specify the " types " 

 of genera, for opinion differs in many cases in which I have made no 

 original study of the matter, and I do not care to adopt or reject con- 

 clusions without some verification. Usually Mr. Grote has been fol- 

 lowed except in his use of certain Hiibnerian genera. I do not think 

 that under the utmost latitude the Tentamen should be considered au- 

 thority for a generic term, while the Verzeichniss names so far as ap- 

 plicable must be used eventually. It follows from this that in some 

 cases older generic terms may have to be substituted for those now in 

 use; but I think such cases will not be great in number. 



With this somewhat lengthy explanation of the origin and purpose 

 of the catalogue I submit it to the consideration of lepidopterists gen- 

 erally. 



All the species contained in the National Museum collection are marked 

 with an asterisk (*). I hope that those who have species not so marked, 

 in duplicate, will send specimens to complete the collection for the ben- 

 efit of students generally. The advantage of a central, complete col- 

 lection accessible at all times, constantly cared for, the property for all 

 scientific ends of students generally, can not be overestimated. 



JOHN B. SMITH. 



KUTGERS COLLEGE, April 5, 1892. 

 6048 No. 44 2 



