l6o ENTOMOLOGICAL NEWS. [May, '03 



Careful study of the species leads the writer to the opinion that this 

 species is the same as C. cana, of Erichson. 



In the description of C. cana, Erichson says that it is "very similar in 

 form and marking to the Brazilian C. hypermnestra, the upper sides of 

 the wings especially so, with the male more brownish gray." 



A specimen of C. cana, identified by Strecker, in the writer's collec- 

 tion, is identical with C. floridana. Examination of specimens of C. 

 hypermnestra, identified by Staudinger, show the close relationship with 

 C. cana, in so much so, that if the specimens were brownish gray, they 

 would correspond to the description of C. cana, by Erichson. 



If, therefore, Strecker's identification of the writer's C. cana is correct 

 and that of Staudinger for C. hypermnestra is correct and the description 

 of C. cana, by Erichson exactly answers that of C. floridana, thenitseems 

 clear that C. floridana falls naturally into the synonymy of C. cana 

 LEVI W. MENGEL, Reading, Pa. 



SPIDERS AS ENEMIES OF DRAGONFLIES. [The suggestion made in the 

 February NEWS, page 34, on this subject, has called forth the following 

 remarks]. As to the possibility of there being some relation between ten- 

 erals in spider's webs and scarcity of imagoes. I doubt if the spiders are 

 a very important factor. That is, in the boat house possibly, a consider- 

 able percentage of emerging species were captured, but the total num- 

 ber emerging in the boat house was relatively small to the total number 

 emerging under more favorable conditions (no spiders) elsewhere. In 

 the genus Gomphus, on several occasions, I have found apparent scarcity 

 of imagoes due to the fact that they frequented unsuspected spots. For 

 example, once in Tennessee I spent the day along the Cumberland. The 

 river had been rising and falling so all exposed mud banks were wet and 

 sticky. Up these mud banks nymphs of G. vastus had crawled and were 

 crawling in great numbers. Many became so coated with mud that, this 

 drying, they failed to emerge. Occasionally very recent tenerals would 

 be shaken from bushes or grasses, but no imagoes were seen flying freely 

 about during the day. That afternoon, as I was going home, about half 

 a mile from the river, on a thinly wooded hillside, with a western expos- 

 ure, bright in the light of the low sun, I found vasttis literally by hundreds. 

 They were abundant in a restricted area possibly 100 yards long by 50 

 yards wide. I have had a somewhat similar experience with G. crassus. 

 A friend of mine found Cordulegaster common in a ravine ; a few days 

 later not one was to be seen. Dromogomphus spoliatus, along the old 

 canal-feeder at Ft. Wayne during the middle of an August day, may be 

 very abundant, but they are not to be found at 8 A. M. and 5 p. M. they 

 have completely disappeared. You have noticed how dEschna and Ana.r 

 will be found one day in flocks over fields and the next day not one ran 

 be seen. Moreover, in Indiana lakes I believe that the life of the nymph 

 is as precarious and as full of vicissitudes as the life of the imago, and a 

 wholesale destruction of tenerals would hardly permit of the balance 



