a bearing upon wider questions than the separation of species, 

 namely, geographical distribution and descent. 



In the different families we are obliged to use different char- 

 acters as the basis for genera, and even in different sections of 

 the same family. Thus in a large number of genera in the Noc- 

 tuidte, it needs only a careful study to apprehend quite strong 

 characters, such as armed tibiae, hairy eyes, a pitted or roughened 

 and tuberculate clypeus. But among several genera below Hom- 

 optera and among the Deltoids, the characters tend to become 

 comparative. In this latter group the tibiae are always unarmed 

 and the eyes naked, and where we have simple antennae and no 

 peculiarities such as distinguish Rcnia, ZanclognatJia and Palla- 

 chira, we have to take comparative differences. In Capis, for 

 instance, a glistening, pyralidous Deltoid, we have merely the 

 broader, squarer fore wings and the difference in the labial pulpi 

 to distinguish it from Sisyrhypena, which in habit it resembles ; 

 although it is probable that the male antennae are also simple, and 

 that there are some differences in the neuration which I have not 

 worked out yet. I cite this merely as an example of the varying 

 characters of genera in the group. In this list, then, I have most 

 frequently adopted genera which I have studied, and, upon one 

 ground or another, have been convinced of their validity. I hope 

 the student, after arranging his material, will be tempted to 

 investigate its structure and literature for himself. He will un- 

 doubtedly discover many new facts which will here and there 

 lead to changes. Let him but compare this list with the Smith- 

 sonian catalogue and he will at first hardly recognize them as 

 referring to the same fauna. It is hoped now that we are on the 

 road to more accurate knowledge. It is a pity that in this 

 study so much personal difference finds expression. Without 

 having attained the ideal, I have held before my mind the picture 

 of a student without prejudice and incapable of concealing the 

 sources of his information ; one who, in his interpretation of 

 Nature, is courteous and fair towards all those engaged in the 

 same quest. 



I do not wish to allow my " New Check List " to go to the 

 press without my acknowledgment that I have made, with most 

 students, a great many mistakes. Considering the circumstances, 

 and looking back over many years during which I had no one to 

 help me with determinations, so that I was obliged to make out 

 the genera and species as I could, I am surprised I did not make 

 more. With regard to my species, though very numerous, I 

 think they are very generally known ; partly because I have de- 

 termined for others so much, and partly, I hope, that my descrip- 

 tions are recognizably written, to say nothing of the Plates which 

 I have published illustrating the subject. 



