62 University of Michigan 



5. Philip P. Calvert, The Fossil Odonate Phenacolestes, 

 with a Discussion of the Venation of the legion Podagrion 

 Selys. Proc. Acad. Nat. Sci. Phila., Alay, 1913. 



6. A. S. and P. P. Calvert, A Year of Costa Rican Natural 

 History. The McMillan Company, 1917. 



7. F. Ris, Neuer Beitrag zur Kenntnis der Odonatenfauna 

 von Argentina. Mem. Soc. Ent. Belg., 1913. 



8. F. Ris, Odonata from the Region of the American 

 Cordilleras between Costa Rica and Catamarca. "An entire 

 installment of the Archiv f. Naturgeschichte." (Letters from 

 Dr. Ris, December 30, 1917, and April 10, 1918. The paper 

 includes a catalogue of the Odonata of Colombia. Dr. Ris 

 had seen proofs of some plates of wing photos when he wrote 

 me in 1917. I have not seen the paper, but Dr. Ris has sent 

 me a copy of that part of the manuscript dealing with Het- 

 eragrion.) 



9. Helen T. Higgins, The Development and Comparative 

 Structure of the Gizzard in the Odonata Zygoptera. Proc. 

 Acad. Nat. Sci. Phila., January, 1901. 



10. George H. Carpenter, The Geographical Distribution 

 of Dragonfiies. Scientific Proc. Royal Dublin Society, April, 

 1897. 



A few other references to the genus or to certain species 

 are not of interest in the present study. 



Appendix 



Several weeks after the above paper was completed and 

 sent to Dr. Ruthven for publication, I received a package of 

 separates from Dr. Sjostedt, one of which^* contained mat- 

 ter of special interest in this connection. In this paper 



" Wissenschaftliche Ergebnisse der — Schwedischen Entomologeschen — Reise 

 des Herrn Dr. A. Roman — in Amazonas 1914-1915 — i Odonata — von Yngve 

 Sjostedt. Arkiv for Zoologi, Band 11, N. 15. 



