148 ENTOMOLOGICAL NEWS. [May, '06 



sity in these parts, and many species have the body colors 

 very brilliantly and diversely developed. 



In the genus Gomphus as it occurs about my home at Bluff- 

 ton, Indiana, it may be noted that all species are colorless- 

 winged ; certain ones are of about the same size ; these certain 

 ones occur at the same season, at the same place, have appar- 

 ently identical habits and are very similar in body markings. 

 Under these conditions the complexity of the copulatory act 

 is probably the only barrier to the free intermingling of these 

 species. I have already in the ENT. NEWS described a hybrid 

 of graslinellus and sordidus ; and during the season of 1905 a 

 number of specimens were taken which, in the opinion of Dr. 

 Calvert and myself, are specifically indeterminable, combin- 

 ing characters of both crassus and fra tern us, two closely related 

 species in which the abdominal appendages of the males are 

 very similar. Both species were flying at the ripple where the 

 indeterminable specimens were taken. Dr. Kellicott once re- 

 marked that he could not understand how, among the Enallag- 

 mas at Cedar Point, Ohio, the males could recognize their own 

 species of the opposite sex, and he studied many specimens 

 carefully but without discovering any evidence of hybridiza- 

 tion so far as I know. The coupling of different species has 

 been reported a number of times but I know of no record of 

 copulation. However, near Bluffton, Enallagma civile and 

 carunculatum , two species with very similar appendages are 

 brought in contact in numbers about a 6-acre pond. I have 

 studied probably 500 males from this pond, and have found a 

 few specimens (20-30 possibly) which were clearly inter- 

 mediate. 



II. BY- PHILIP P. CALVERT. 



(With Plate VII) 



Mr. Williamson has asked me to add any notes or sugges- 

 tions which occur to me on the subject of his paper. 



I can confirm his observations in the cases of Aeshna con- 

 stricta and Sympetrum viciniim. The former is illustrated by 

 Plate VII, based on a photograph from specimens in my collec- 

 tion labeled, "Taken in this position (of copulation) Oct. i, 



