Generic characters of the south american Corduliidae, with descriptions of the species found in the Guyanas

This study contains the results of an examination of the Corduliidae found in the Guyanas. It is based on a critical study of the data as published mostly in the older literature and on the identification of the material brought together in Surinam in the years 1940 to 1965 by Mr. J. Belle and myself, beside some specimens picked up in French- and in (Br.) Guyana. Comparison of three types in the Selys collection in the Brussels Museum, of one in the Fraser collection in the British Museum (Nat. Hist.) in London and of one kindly received from the Museum in Berlin was necessary to eliminate further confusion. It now became clear that, so far as the material goes, one genus (here described as new) belonging to the Gomphomacromiinae and two genera of the Corduliinae inhabit the Guyanas. Among these the female allotype of Paracordulia sericea Selys is described and of the genus Aeschnosoma the male allotype of Ae. elegans Selys and Ae. auripennis as a new species in the female sex only, whereas the larva of Ae. forcipula Selys and of Ae. auripennis n. sp. are described for the first time. It is a well known fact that the Corduliidae are poorly represented in South America, in contrast with North America and the Old World, where they are represented by numerous genera and a great number of species. In his well known work on the Odonata in Biol. Centr. Am. (1892-1908), Calvert states the practical absence of this group in the present fauna. Ris (1918) arrives to the same conclusion in his study on the Odonata of the South American Cordilleras, when he says that the Corduliidae in that region are very poorly represented in comparison with the other families. Cowley (1934) mentions that among 700 specimens of dragonflies, received from Perú, there was but one Corduline. In our collection of about 20,000 specimens of Odonata from Surinam, the total number of Corduliidae imagines amounts to no more than 50, that is 0.2%.