2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64. 



habits is practically nothing. Mr. Brimley has said to the writer 

 that his captures were usually made in open sunny glades of the 

 woods, sometimes long distances from water. Two individuals ap- 

 pear, from the records, to be the largest number seen at one time. 

 Mr. Brimley's captures range in season from March 18 to April 17. 

 My finding of this single exuvium at the Country Club lake shows 

 that a muddy, warm pond is one of the places possible for the 

 naiad and that the female willingly uses such a place for oviposition. 

 for there were several woods streams of various sizes in the neigh- 

 borhood which might have been chosen, if she had been partial to 

 streams. 



HelocorduUa selysii is one of several rare North American dragon- 

 flies that have an early spring season. Those of this early spring 

 group which the writer has studied appear to be very primitive. 

 In some instances, as in this, the genus is small in number of 

 species and is primitive as a whole ; in other instances the early 

 spring species is primitive in its genus, which may be large and 

 have other more modern and more highly specialized species 

 which come later in the season. Examples of primitive species 

 in large genera are Ischnura posita, Aeschna matuta^ Lihellula 

 jesseana, etc. One wonders why these are so illy adjusted to our 

 present seasons. Apparently our longest warm season is not 

 long enough for them to mature a brood. Are they left overs 

 from that pre-Miocene time, when the warm season was prac- 

 tically continuous throughout the year? The other explanation 

 of this early spring emergence is that these may be specialized, that 

 emergence so early gives the adult an uncrowded habitat. This lat- 

 ter explanation does not agree with the writer's observations, which 

 are that few, if any, dragonfly habitats ever sujffer from lack of 

 food for the adult. Crowding may occur among the naiads as they 

 are confined to specific bodies of water, but the season of the adult 

 would not seem to be related to this. 



Of the two species of Helecordulia selysii and uhleri, selysii has 

 the more generalized appendages. These curiously enough are almost 

 identical with those found in another primitive Corduline, Didy- 

 7no'ps^ which, however, Needham ^ and AVilliamson ^ as well as Mar- 

 tin * place in a different division of the subfamily Cordulinae. Per- 

 haps Relocovdulia and Didymops are each more primitive in their 

 respective groups than has been suspected by systematists.^ 



- Needham, Critical Notes on Uie Classitication of the Corduliinae, Ann. Ent. Soc. Amer., 

 vol. 1, pp. 273-280. 1908. 



3 Williamson, A new Dragonfly belonging to the Cordulinae, and a Revision of the 

 Classification of the Subfamily, Ent. News, vol. 19, pp. 428-434. 



■*• Martin, Les Cordulines, in " Collections de Selys." 



^ The writer believes that the male appendages should be considered as a check on 

 venation in any study of the phylogeny of this subfamily. That such curious things as 

 Oordnle^hya and Synthemis are apical specializations and not as primitive as some of 

 their venational characters would .suggest. 



