Grote.] *^"o [Oct. 18, 



edge of the island-like patch of paleozoic rocks near Doylestown, in fact 

 does not go through the Chalfont cut at all ; but nevertheless probably 

 passes within a hundred yards north of it, as is shown by neighboring 

 rock exposures on tlie other side of the fault and by changes in the 

 color and character of the soil. There is no reason to suppose that the 

 fault, great as it is, heaves in the least the trap dike that does probably 

 exist pretty close north of it ; and the trap that occurs within two miles 

 and a half south of the fault at four or five miles to the east must un- 

 doubtedly belong to quite a separate dike. Instead of one great dike 

 there seem to be several smaller ones not continuous nor quite in line. 



On Apatela. 



By A. RadcUffe Grote, A.M. 



{Read before the American Philosopldcal Society, October IS, 1S95). 



The genus Apatela has awakened considerable interest on account of 

 the diversity of types among the larvae of the different species. As will 

 be seen from my lists of the N. American species, these greatly exceed in 

 number the European, and probably afford a larger number of these larval 

 types ; while nearly all of the European groups are represented in North 

 America, the Agrotid fauna of the two continents being, as often insisted 

 upon by me, closely related. It follows that our nomenclature is derived 

 chiefly from European sources. It may be said that the Apatelidae are 

 difBcult to distinguish from the Arctiidae, by exclusive characters drawn 

 from the imago. 



I have only quite recently become acquainted with the extremely beau- 

 tiful work of Dr. T. A. Chapman, on the genus Acronycta (Apatela) and its 

 allies, London, 1893, a publication which at once placed its author 

 among the foremost of the students of the new Lepidopterology, a school 

 which has entirely broken with the old system under which the study had 

 become sterilized, and was in danger of passing entirely into the hands of 

 fanciers and dealers, at least in Europe. The results of the New School 

 may be estimated by the statement, that the spectres of the metaphysical 

 groups " Bombycidae," " Zygaenidte," "Noctuidae," "Tineidae," which, 

 especially the former, haunted our nomenclature, have been effectually 

 exorcised. The " Bombycid;xi " have been shown to be composed of 

 families belonging to no less than three superfamilies : Bombycides, 

 Agrotides, Tineides ; the results attained through phylogenetic and onto- 

 genetic studies are now applied to classification. 



In my list published in these Proceedings in 1883, I had separated the 

 three families of which the " Noctuidte " were then composed, and this 

 classification is the basis of the catalogue published as Bulletin No. 44, of 

 the National Museum, Washington, 1893. Recent sttidiesof Mr. Harrison 



