xxxiii,'22] ENTOMOLOGICAL NEWS 105 



The Phylogeny and the Geographical Distribution of 

 the Genus Libellula (Odonata). 



By CLARENCE HAMILTON KENNEDY, Ohio State University, 



Columbus. 



(Continued from page 70.) 



Group 8. (a) Composita Hagen. PI. IV, fig. 15. Wyoming and 

 Utah to southeastern California. A semidesert species of alkali 

 sloughs. (?) 



At Laws, California, August 20, 1915, in the very alkaline 

 Owens Valley, east of the Sierra, this species was found ovi- 

 positing in a very alkaline seasonal or temporary, grassy slough 

 made by waste irrigating water. No data were gathered as to 

 whether the species succeeded in maturing in such a place. 



This remarkable insect, which has spread probably from the 

 dry areas of southern California, where there seems to have 

 been a sanctuary for several primitive Odonates, stands inter- 

 mediate between Group 7 and Group 8. In the penis, coni- 

 posita resembles Group 8, but in size and color of wings and 

 body it is related to Group 7. The homologies of the parts of 

 the penis in Group 8 were inexplicable until the penis of 

 composita was examined. In it all the parts already found in 

 the generalized sanifasciata penis are recognizable. It is highly 

 specialized in the large lateral lobes and the arched cornual 

 base, but is very primitive in that the three cornua are still 

 recognizable though rudimentary. The pattern of the wing 

 markings suggests nodisticta, Ladona and the Eurasian species 

 in which the wing markings are reduced or perhaps have never 

 been greater. The insect is highly specialized in its pearly 

 white eyes, the white costal border and perhaps in its curious 

 habit of flying about in tandem with its mate. Its very re- 

 stricted and erratic distribution shows it to be a relict. Just 

 how it is related to the species of Group 8 is a question, but 

 there is no doubt that it is associated with their ancestry. 



Group 8. (b) Jesseana Williamson. PI. IV, fig. 1(J. Enterprise, 

 Florida, April 22, 1921. Known only from a single pond, when- 

 Jesse Williamson found these mating and ovipositing. (See Ent. 

 News, xxxiii, pp. 13-17.) 



