Occasional Papers of the Museum of Zoology 9 



In Desmogomphus we have the most primitive genus of the 

 series. The front wing of this genus if considered alone could 

 as well be referred to the Epigomphus series. At the opposite end 

 of the series is the densely veined Gomphoides stigmata, for example. 



Four genera (if Calvert's views on synonymy, Biologia Centrali 

 Americana, are followed) containing about sixty species comprise 

 this series which is Neotropical with a few species which have 

 penetrated into the Nearctic Region. 



3. The Gomphus series. — This includes the grand genus Gom- 

 phus of de Selys less the Epigomphus series. It is the dominant 

 gomphine type in the world at the present time, being represented 

 by more than thirty genera and two hundred and fifty species. 

 It is well represented in all the zoogeographical regions except 

 the Neotropical, where only one genus in the south and one in the 

 north occur. It holds a place in the subfamily similar to the 

 position of the tribe Agrionini in the Agrioninae. Associated with 

 uncrossed triangles, supratriangles, and subtriangles is a reduction 

 and specialization in the cross-veins between Mi_3 and M4 (see 

 Davidius under the Hagenius series). This last character is unique 

 in the Anisoptera (see the Hagenius series) and can hardly be 

 associated with greater wing efficiency. The Gomphinae gen- 

 erally, while capable of swift and mobile flight, spend a relatively 

 small portion of their lives on the wing when compared with some 

 of the aeshnines, cordulines, and libellulines, and the genera of this 

 series are no exception to the rule. However the reduction in the 

 venation has been brought about, the fact remains that here we 

 have a different condition from that found in the two preceding 

 series where the higher members are the more densely veined. 



The series is very compact and the venational differences 

 between genera are slight. 



4. The Zmiophora series. — Zonophora, the single genus of this 

 series, is characterized by the triangles and subtriangles of fore 

 and hind wings similar, the triangles long and once crossed, the 



