8 PREFACE. 



embrace species of Eadena, Mamestra, Tieniocampa aud otliers under 

 one term, while closely allied si^ecies may be widely separated under 

 different generic names. Mr. Butler has not, to my knowledge, given 

 any key to his classification, and criticism is therefore impossible. I 

 wish simply to call attention to the fact that in this collection the 

 arrangement of the species is on a unique basis, and that few of the 

 generic associations are pure, according to German, French, and Ameri- 

 can definitions. Judged by these standards the arrangement is an ut- 

 terly unscientific hotchpotch. In the course of this rearrangement, 

 Mr. Butler has united the Grote and Zeller material with the old col- 

 lection, forming one series. The Walker types are ascertained and 

 the printed label associated with the specimen is placed on the pin. 

 If the Walker name has priority, a "type" disk is pinned next to 

 it. If the name is a synonym, the " type " disk is put on the pin with 

 the insect and with the printed label. In all cases where the type of 

 a species is in the series a "type" disk next the specimen calls atten- 

 tion to it. This greatly facilitates the search for sx)ecies, and my task 

 was considerably lightened by my ability to compare the Guenee, 

 Walker, and Grote types side by side. Mr. Butler has published crit- 

 ical and synonymical notes on the species so far as arranged, much the 

 greater part of them in the " Entomologist," since my visit to the 

 Museum. In the majority of instances the associations are correct; 

 but much of the synonymy given was already known, and in that which 

 is new there are some bad errors, caused by the failure to compare 

 structural characters and relying only on an apparent, superficial re- 

 semblance. But many species were yet left unidentified with the other 

 American material. In those parts of the collection not yet arranged, 

 the work was more tedious and involved more labor. There was an 

 advantage, however, in the fact that the arrangement was according to 

 Walker's catalogues and it was thus easy to find the specimens, little 

 as the association might be warranted. Mr. Butler in his rearrange- 

 ment seems to have preserved, as far as possible, every original label 

 that would indicate or aid iji identifying a type and has additionally 

 marked those specimens that he considers as such. 



I thus made my studies under exceptionally favorable circumstances. 

 The Grote collection is really the basis of the nomenclature in Ameri- 

 can collections generally, and a very great point was gained when I 

 •could identify the Guenee and Walker names with the Grote names for 

 the same species. In addition, I had with me a small series of speci- 

 mens generally unnamed in collections, or of which I was doubtful, 

 and these were carefully compared. A full set of my own monographic 

 papers enabled me to verify the correctness of the identifications there 

 made, and a series of notes and drawings aided me in other groups. In 

 the Deltoids I had drawings of nearly all the species as they are named 

 in the National Museum, and these were carefully compared and the 

 synonymy noted. I think 1 can claim a familiarity with a very large 



