574 TRANS. ST. LOUIS ACAD. SCIENCE. 



long were in this country." Through the kindness of Mr. Wm. 

 Buckler of Emsworth, and of Mr. J. Hellens of Exeter, Eng., 

 who have furnished me specimens, I ;am able to state that this 

 surmise has been fully justified. A more careful study of the 

 European A. cescularia, than had hitherto been made, shows it to 

 agree with pometaria in structure and habit. The eggs have the 

 same general form and are laid in the same regular manner ; the 

 larva has the third pair of prolegs (overlooked by former describ- 

 ers) on the 8th joint ; the chrysalis is formed in a similar silken 

 cocoon, and in both $ and ? is undistinguishable from pometaria 

 except in the rather more distinct punctations on the abdomen.* 

 While the two insects agree so well generically, cescularia is at 

 once specifically distinguished by the eggs being somewhat broad- 

 er, more rounded, less compactly pressed together, of a reddish- 

 brown color, and particularly in being partly covered with hairs. 

 The larva, while found on Elm, as \% pometaria, feeds also on Oak, 

 Lime and other trees, and has different colorational characters,! 

 and the female is at once distinguished by a conspicuous anal 

 tuft of hairs, which supplies those with which her eggs are cov- 

 ered. Yet the males of the two species bear such close resem- 

 blance that the best entomologists would be somewhat puzzled to 

 separate a dozen of the least typical of each, if mixed together. 

 The European species is, on an average, rather larger, lighter 

 colored, and has the pale transverse band of secondaries more 

 bent, especially on the underside. 



In his "Monograph of the Geometrid Moths," published last 

 year under the auspices of Dr. Hayden's Geological Survey of the 

 Territories, Dr. A. S. Packard, Jr., gets badly confused on our 

 two American Canker-worms. Although the misleading nature 

 of Dr. Harris's language regarding the two species had been 

 pointed out by Mr. Mann and myself (a///<?, p. 273), Dr. Packard 

 nevertheless falls into the old error of concluding that Harris's 

 pometaria is Peck's vernata. He does not stop here, however, but 

 heightens the confusion that had once existed but had at last been 

 dispelled, by re-christening pometaria with the new name of autum- 



* I have described the chrysalis of pometaria as not pitted, but there is a very faint, more 

 or less obsolete, punctation observable on more careful examination. 



t Mr. Hellens has published a full description of it in £ni. Afont/ily Ma^., London, Oct. 

 1877, p. 114. 



