ne Ohio VS(^aturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State University. 

 Volume X. MAY. 1910. No. 7. 



TABLE OF CONTENTS. 



WiLLiASisox— A New Species of Celithemis (Order Oiloiiata) 153 



Laughlin — Tweuty-flve Rare Plants at Bariiesville, Ohio 160 



Paeker— Notes on the Nesting Habits of Bembex Ntiliilipennis 163 



O'Kane— The Ohio Powdery Mildews 166 



A NEW SPECIES OF CELITHEMIS (ORDER ODONATA). 



E. B. Williamson. 



While calling on Professor Hine at the Ohio State University 

 last autumn he showed me -i specimens of Celithemis collected by 

 himself at Slidell, Louisiana, July 2-6, 1905. The species was 

 unknown to both of us, and he very generously turned the 

 material over to me for study. This study had not progressed 

 far when it became evident that the real difficulty would lie in 

 determining which of two species Kirby had before him when 

 he described his Celithemis fasciata, to which species numerous 

 specimens from Ohio and Indiana collected by Kellicott and his 

 students and co-laborers had been referred. In working out 

 the differences between the northern (Ohio and Indiana) speci- 

 mens and those from Louisiana, however, it became clear that 

 the name fasciata would have to go to the southern species, and 

 that the better known northern species required a new name. I 

 informed Professor Hine of this and he kindly requested me to 

 complete the study and send him the paper for the Ohio Natur- 

 alist. 



Reasons for assigning Kirby 's name fasciata to the Louisiana 

 specimens and describing the Ohio and Indiana specimens, for- 

 merly called fasciata, as a new species, niononielaena: 



1 and 2. In Kirby's description he says: "Triangle (front 

 wing) crossed by one or two nervures, followed by 4 rows of cells." 

 His figure shows the triangle with 2 crossveins and 4 posttrigonal 

 cells on each side. (It is possible that the venation shown in 

 the figure has one side duplicated on the opposite side by the 

 artist.) Referring now to these characters in the material before 

 me I find that the 4 Louisiana specimens (fasciata) have 5 front 

 wings with 2 crossveins and 3 wings with 1 crossvein in the triangle _.——--- 



153 /C^^^L'^ 



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