PHILIP P. CALVERT. 27 



BURMEISTER'S TYPES OF ODONATA. 



BY PHILIP P. CALVERT, PH. D., 



Justructor in Zoology, University of Pennsylvania, Philadelphia.* 

 (With Plate I.) 



Origin of the Present Paper. 



In brief " Preliminary Notes on some African Odonata" pub- 

 lished in volume xix, of these Transactions, June, 1892, I made 

 the remark, " The two species of Orthetrum here described as new 

 may possibly be among the species already described by Burmeister 

 or Rambur, but from their descriptions I could not satisfactorily 

 identify them." And, in connection with the fuller descriptions of 

 the same two Orthetra, contained in the Proceedings of the United 

 States National Museum, volume xviii, the hope was expressed (p. 

 130) " that the present descriptions and figures will sufficiently char- 

 acterize the species in question, so that those having access to types 

 of previously described species may perceive the identity, if it exist." 



If any one had perceived the identity, no published statement of 

 the fact had appeared up to the Winter of 1895-'96, at which time 

 I was studying in the University at Berlin. Dr. (and now Profes- 

 sor) Ferdinand Karsch, the well-known entomologist, of the Museum 

 fiir Naturkunde in that city, then told me of the existence of some, 

 at least, of Burmeister's types of Odonata in the Zoological Institute 

 at Halle. Dr. Karsch had also experienced the difficulty of satis- 

 factorily identifying African species of Orthetrum described by va- 

 rious authors. I was then planning to spend the Summer semester 

 of 1896 at Jena, and when I suggested to Dr. Karsch that the 

 short distance thence to Halle, might enable me to spend the Pfing- 

 sten, or Whitsuntide, week of holidays in an examination of such 

 Burmeisterian Orthetra as might yet exist in the latter place, he was 

 pleased to approve of the suggestion. 



Accordingly, having first obtained the permission of the late Prof. 

 Ernst Ludwig Taschenberg, then Professor of Entomology, I spent 



••■■ Researches made in the Zoologisches Institut of the Vereinigte Fried richs- 

 Universitiit Halle-Wittenberg, at Halle, Germany, and in the Museum of Com- 

 parative Zoology, Cambridge, Massachusetts. 



TKANS. AM. ENT. SOC. XXV. MAKCH. 1898. 



