The karyotypes of some Anisoptera from Surinam

The male germ cell chromosome complements are described and illustrated of the following 25 spp. from the surroundings of Paramaribo, Surinam, 16 of which (asterisked) have not been previously examined cytologically: Gomphidae: Phyllogomphoides undulatus (Needham)* (n= 12, m), Zonophora calippus Sel.* (n= 12, in); — Aeshnidae: Anax concolor Brauer* (n= 14. m). Coryphaeschna viriditas Calv.* (2n=23; n=!3. XO; n=!4, in): — Libellulidae: Anatya guttata (Erichs.)* (n= 13), Diastatops pullata (Burnt,)* (n=!2. in), Dythemis williamsoni Ris* (2n=22. neo-XY; n=l I, neo-XY; n=!2. neo-XY; n=!3, in. XO). Erythemis credula (Hag.)* (n=l3. in). E. haematogastra (Burnt.)* (n= 13), E. peruviana (Ramb.)* (n=!3), Erythrudiplax b. basalis (Kirby) (n= 13. no in in the Surinam specimen, but it occurs in material from Bolivia and Brazil), E. connata fusca (Ramb.) (n=!3, in). E. paraguayensis (Foerst.) (n=!3, in. but n=12, without m from Bolivia). E. umbrata (L.) (n= 13, in). E. unimaculata (de Geer) (n= 13, m uncertain). Lepthemis vesiculosa (Fabr.) (n=13), Micrathyria eximia Kirby* (n=l3, m). Oligoclada amphinome Ris* (n= 13, in). Orthemis aequilibris Calv.* (2n= 12. n=6, neo-XY). O. ferruginea (Fabr.) (2n=25, 2m, XO; 2n=23, m, XO; n=!2. in. XO: n= 11, m. neo-XY; n=IO. neo-XY). Rhodopygia geijskesi Belle* (n=l3. hi). Tramea binotata (Ramb.) (n=!3, in), Uracis imbuta (Burm.) (n= 13. in). Zenithoptera americana (1.,)* (n=13, in), and Z. fasciata (L.)* (n= 13, in). — It is argued that the genus Dythemis, viewed as a whole, appears cytologically peculiar within the subfamily, and that the evidence on the cytogenetic features of O. ferruginea is in good agreement with its general morphological variation and unusually wide geographic range.