March, 1922.] Chamberlin : The Genus Pcecilo'nota. 53 



Up to the present time, despite the fact that only nine species have 

 been described from our territory, there has been much confusion and 

 many specimens have been sent out erroneously named. Of the nine 

 described species four must be placed in synonymy and the status of 

 a fifth (debilis Lee.) is doubtful. 



A considerable series of species belonging to this genus has been 

 examined from all parts of the United States and Canada, and where 

 it was impossible to examine specimens, as in the case of debilis Lee, 

 and bridzvclli Van Dyke, photographs and drawings were obtained. 



The following names have been applied to species occurring in the 

 United States : 



1. P. tliureura Say 1832. 



2. P. cyanipes Say 1836. 



3. P. costicollis Gory 1841. 



4. P. erecta Gory 1841. 



5. P. ferrea Melshcimer 1844. 



6. P. debilis Leconte 1859. 



7. P. cupripes Casey igog. 



8. P. parviceps Casey 1909. 



9. P. bridivelli Van Dyke 1918. 



Of the above names, numbers i, 2, 5 and 9 represent valid species, 

 and from the evidence at hand number 6 would seem to represent a 

 distinct species. In addition to the above, two very distinct species are 

 here described for the first time, and a third species is mentioned 

 which may be but a geographical variety. 



Over two hundred specimens have been examined, and with the 

 exception of P. cyanipes Say, which shows wide variation, the various 

 species seem to be quite constant and should be easily identified with 

 the aid of the descriptions and figures here presented. 



The sexes may be separated by the size and shape of the emargina- 

 tion of the last ventral segment. 



The habits of the species, so far as known, are quite similar. The 

 eggs are deposited in the bark of trees and the larvae mine in the 

 cambium and trunk of the hosts. 



The larvae are of the typical flat-head type, having the first segment 

 distinctly larger and broader than those which follow. The dorsal and 



