130 CONNECTICUT GEOL. AND NAT. HIST, SURVEY [Bull. 



reaching only to caudal margin of the first abdominal segment; 

 inferior anal appendag^es of the male bifid. 



Literature dealing with Ophiogomphiis has been published by: 

 Woodruff, L. B. Journal of the New York Entomological Society, XXII : 



61-63: 1914 (Nymph). 

 Needham, J. G. Canadian Entomologist 29: 166: 1897, pi. vii : 31: 233- 



238: 1899, pi. V. 

 Bromley, S. W. Entomological News 35 : 343-344 : 1924, pi. xi. 

 Calvert, P. P. Entomological News 3^: .34.'?-346: 1924, pi. xi. 



The classification of this genus is in a very unsatisfactory con- 

 dition, probably due to the unusual variation in the characters 

 commonly relied upon. A thorough study of the group is needed, 

 based on numerous specimens of each species, which should include 

 both sexes properly associated. Until this is done the identifica- 

 tion of our Eastern Ophiogomphi will remain a very uncertain 

 proposition. 



Like other members of the family, the genus Ophiogomphus has 

 the peculiar habit of apparently emerging in large numbers in 

 certain localities and then disappearing quickly — a sort of explosive 

 dispersal or disappearance. Only in a few cases have they been 

 found in large numbers. According to Woodruff the nymphs 

 inhabit small clear brooks with sandy bottoms. 



Key to Species 



Nymphs" 



I. Dorsal spines rudimentary aspersus 



rupinsulensis 

 carolus 



Dorsal spines prominent colubrinus 



mainensis 



Adults, Males" 



1. Inferior anal appendage viewed from below with arms not greatly 



widened at apices and without an angle on the dorsal surface in 



lateral view 2 



Inferior anal appendage viewed from below with arms greatly 

 widened at apices ; or with an angle on dorsal surface in lateral 

 view 3 



2. Accessory genitalia as in Fig. 16, No. 7; wings slightly flavescent 



or yellowish howei 



Accessory genitalia as in Fig. 14, No. 10; wings clear anomalus 



3. Inferior anal appendages narrower than the superiors and invisible 



when viewed from above 4 



Inferior anal appendages wider than the superiors and visible from 

 above 5 



4. Metapleural suture lined with black; superior anal appendages as 



in Fig. 14, No. 3 aspersus 



Metapleural suture not lined with black; superior anal appendages 

 as in Fig. 14, No. 2 rupinsulensis 



^* Nymphs of howei and anomalus are unknown. 



1' Colubrinus adults are distinguished from others mainly by the black stripe present 

 on the front at base of antennae. 



I 



