OF NORTH AMERICA. 239 



ETJPREPIA AMERICANA. (Page 95.) 



This name must give place to Euprepia caja, tlie burden of proof 

 being conclusive as to the identity of the European and American 

 insects. The white collar, which appears to occur in all American 

 specimens, and which was mainly relied upon by Harris and subse- 

 quent writers, as the most available point of distinction, occurs, more 

 or less strongly marked, in many European specimens, as has been 

 proved to me by Dr. Standinger, of Dresden, and Mr. Strecker, of 

 Reading. To the former entomologist I am indebted for a very beau- 

 tiful suite of the variations of this insect. It has often been urged that 

 American insects, merely on account of their wide geographical sepa- 

 ration from Europe, must be different from their near representatives 

 in that country. Of the fallacy of this view I am more and more 

 strongly convinced, especially as regards those forms which are found 

 in the more northern regions of both continents. Of this, E. caja 

 may be taken as one instance, and Arciia Quenselii as another, while 

 it is impossible to draw a definite line between Phragmatobia rubricosa, 

 Harris, and the European form of P. fuliginosa, which occurs in 

 Lapland, and is known as var. borcalis. We know that many noctuse 

 occur in both countries, as Scoliopteryx libairix, and why not also 

 species of Bombycina. The Zygsenina are less likely to occur in both 

 countries, because they do not range into arctic regions. This view is 

 strongly supported by the marked similarity between the entomological 

 fauna of the northern Pacific Coast of America and that of Europe, 

 which we might naturally expect to occur on account of the intimate 

 connection of the two continents in the Arctic Zone. This is much 

 more decided than on the Atlantic border ; and it is reasonable to 

 suppose that these forms, which are alike in both continents, have 

 been disseminated through this medium. Unfortunately, we know 

 but little comparatively of British Columbia, Washington Territory, 

 and Oregon, and it will be of much interest to watch the progress of 

 discoveries in those countries, as bearing on this question. I hope at 

 some day to enter into this question more fully than is permissible in 

 these pages. 



LEUCARCTIA ACR.a:A. (Page 99.) 

 Through an oversight, all the plates in Part 4 have the lower wings 

 of the female of this species (pi. 4, fig. 2) colored as in the male ; they 

 should be white. 



