1873.] 117 [Scudder. 



As we proceed southwestward from New York, we find that the 

 partially decomposed and disintegrating portion of these rocks 

 which, in the Blue Ridge, lies beneath the clays, has escaped denu- 

 dation, and we at length reach the region in southern Virginia and 

 Carolina, where these clays, the result of complete decomposition, 

 are seen in nearly vertical strata forming the superficial soil. These 

 ancient clays, formed by the sub-aerial decay of the crystalline feld- 

 spathic and hornblendic rocks of the great eozoic continental areas, 

 were, according to the speaker, the source of the argillaceous strata 

 of the cenozoic, mesozoic and paleozoic periods; and in the heights 

 of the southern Appalachians we have still remaining a portion of 

 that eozoic land which has stood throughout all these ages, unde- 

 nuded, unglaciated, unsubmerged, and from its peculiar nature (being 

 composed, as already described, of highly inclined porous and per- 

 meable strata, supporting an abundant vegetation), but little subject 

 to the degrading influences of atmospheric waters. 



Mr. S. H. Scudder exhibited a very valuable collection of 

 the original and unpublished drawings of John Abbot, illus- 

 trating the transformations of our southern Lepidoptera, 

 and supplementary to Smith & Abbot's magnificent "Insects 

 of Georgia." Mr. Scudder hoped to purchase the collection 

 for the library of the Society by subscription* 



Section of Entomology. Oct. 22, 1873. 



Mr. S. H. Scudder in the chair. Twelve persons present. 



Mr. Scudder called the attention of the Section to some 

 recent remarks by Mr. Meldola 1 upon Iphiclides Ajax (Pa- 

 pilio Ajax Auct.). 



These remarks were made in connection with investigations " on 

 the amount of substance- waste undergone by insects in the pupal 

 state ."; it was presumed a priori that, as there was gain of matter in 

 the larval state, and loss during the pupal, the size of an individual 

 of any species " would be, cceteris paribus, inversely proportional to 



i Ann. and Mag. Nat. Hist., xn, (Oct., 1873), p. 301-307. 



