Catalogue of the Odonata of Ohio. 



205 



21. Enallagma divagans Selys. 



Sandusky, June 26, one male ; Licking Reservoir, July 25, 

 not uncommon ; Sugar Grove, September 4, man)' pairs taken. 



The dorsal band on the second abdominal ring is subject 

 to wide variation. Among twenty males taken in one day, 

 only two had the band for the entire length ; the same num- 

 ber had it reduced to a large apical spot, while the remainder 

 varied between these extremes; in a majority it covered 

 two-thirds or three-fourths of the length. There are other 

 interesting variations in its markings, e. g., the humeral 

 stripes are sometimes reduced to exclamation marks, as in K. 

 posita, the blue on sides of 2 and 3, the number and width 

 and amount of interruption of the apical rings on 3-6, the 

 postcubitals vary from 7 to 9. 



The female, it appears, has not been described. The de- 

 scriptions heretofore published refer to one of the forms of E. 

 exulans. The following brief diagnosis may serve to distin- 

 guish the female from others of the genus : Length of abdo- 

 men, 18-20 mm.; hind wing, 14-16 mm. The male has the 

 labrum, anteclipeus, gense, and frons blue, the postclipeus 

 black. The female differs by having the parts that are blue 

 in the male pale to brownish, rest of the head as in the male, 

 i. e., black, with cuneiform, post-ocular spots blue. Thorax 

 black, broad blue stripe each side. The mid-dorsal carina 

 black, the blue stripe not divided by red ; sides blue, second 

 suture black ; femora and tibiae black without, pale within, 

 the hind tibiae with a black line only. Abdomen pale on the 

 sides, with the sternal membrane black, dorsum black, with 

 interrupted apical rings from 3-7; there is a large, oval, api- 

 cal, blue spot on each side of S, the two separated by a narrow 

 black dorsal line; 10 is black. 



In its habits of flight Divagans differs from others of the 

 genus. I have never found a female, and but rarely a male, 

 resting upon or flying about the herbage at a distance from 

 the water. From 10 a. m. to late in the afternoon of favor- 

 able days they may be found pairing and ovipositing, always 

 flying low and resting on floating plants, such as Nymphcea, 

 Potamogeton, or Algcs. It is not often that the female may be 

 seen ovipositing unattended. 



