1892.] ENTOMOLOGICAL NEWS. 



amateur. They have the wing form of Tortricids, and much of 

 their habital appearance, but have the venation above described. 

 Unlike all the other Arctids, however, the internal vein of the 

 primaries is forked at the base. That is to say, two parallel veins 

 start at the base and unite a short distance beyond into the nor- 

 mal single vein. The ocelli are present. We have as yet but 

 two genera with three species described from our fauna, and of 

 these Sarrothripa lintncriana is the common eastern species. 



The Pericopidae are very uncertainly separated from the Arc- 

 tiidas. In venation they differ chiefly in that veins 3 and 4, and 

 7 and 8, of the secondaries are stalked; that is, a single vein only 

 starts at the point of origin, and this divides on its way to the 

 outer margin. The species are often rather frail and long-winged, 

 and have been compared to the Heliconinse of the diurnal Le- 

 pidoptera. Some of the species, American and foreign, which 

 were formerly referred here, have been of late proved to be 

 Geometridae! 



The Lithosiidae differ from the Arctiidae by the absence of ocelli, 

 but agree with them in almost all other structural characters. In 

 the typical genus the primaries are narrow and elongate, while 

 the secondaries are broad and proportionately large, but in our 

 American forms we have all gradations from this to a really geo- 

 metriform wing. It may not be amiss to say that here, too, an 

 interesting amount of uncertainty exists whether some species 

 are not Geometridae rather than Lithosiidse. Some of the spe- 

 cies resemble Noctuidae, and others are sometimes mistaken for 

 micro-lepidoptera. A reference to the venation will, in most 

 cases, settle the question at once. There is a tendency in this 

 family towards a loss of some of the veins of the secondaries, 

 indicating an approach to the Syntomidae, already treated. 



The Arctiidae differ from the Lithosiidae by the presence of 

 ocelli. They are larger, as a rule, but sometimes with very 

 similar wing form. Indeed, almost any desired variety of wing 

 form can be found in this family, which, by its bright and often 

 strongly contrasting colors, is one of the most attractive to col- 

 lectors. Two subfamilies are indicated in the American fauna: 

 the Cydosiinae, which have a roughened or tuberculate front, and 

 the Arctimae, in which the head is normal, not rough or tuber- 

 culate. In many of the species in this family there is a tendency 

 to a reduction in the spurs of the hind tibke, and irdjuently one 

 of the pairs is wanting. 



