254 ENTOMOLOGICAL NEWS. [Oct., '03 



river two or three hundred yards distant. The gravel pit is 

 separated from the river by woodland, and while this male may 

 have left the river to come to the gravel pit, the chances are 

 that it passed its nymphal life in the pit. Both grasliiiellus 

 and sordidtis are on the wing at the same time so, structures 

 permitting, copulation might take place between a male of one 

 species and a female of the other. The isolation of the gravel 

 pit with its few Gomphi might permit of such a mesalliance, 

 utterly impossible along the river with its agressive competi- 

 tion demanding the instant and perfect adjustment of all 

 structures concerned in the two sexes. 



While this male is distinct from any species known to me (I 

 do not know Gomphus lividus), I prefer to regard it as a 

 hybrid for both a negative and a positive reason. Were it a 

 representative of a distinct species more than one specimen 

 should be known. Its habits must be similar to graslinellus 

 and sordidus, neither of which species is difficult to find in re- 

 gions where they occur. With the collecting that has been 

 done in Ohio, Michigan, Indiana and Illinois, more than one 

 specimen should have been captured. As a positive reason I 

 have the fact that the specimen has characters fairly interme- 

 diate between graslinellus and sordidus — two true physiological 

 species. So far as I know no hybrid dragonfly has hitherto 

 been described (See Calvert, Ent. News, March, 1901 ; p. 68, 

 footnote), and I rather hesitate to place Gomphus along with 

 such genera as Quercus of the botanists, and Anas of the orni- 

 thologists, though hybridization might possibly be more ex- 

 pected here than in any other genus of dragonflies in North 

 America.* Hybrid lepidoptera from breeding cages are known, 

 but I do not know whether any such hybrids occur naturally. 

 J*. L<. Graf, D. A. Atkinson and myself took Chrysopha?tus 

 hypophlceas and Phyciodes nycteis in copulation near Pittsburg. 



A comparison of three males, taken in the same locality, 

 representing Gomphus sordidus, G. sordidus X graslijiellus and 

 G. graslinellus is furnished by the descriptions given below 

 and by the plate of figures accompanying this article. 



[* For references to pairing of different species of Odonata, see Trans. 

 Am. Ent. Soc, xx, p. i88 at top, and Ent. News., iv, p. 268.— P. P. C] 



