Onychogomphus geometricus perplexus, Lieftinck, 1935

Lieftinck, M. A., 1935, A Synopsis of the Odonata (Dragonflies) of Sumatra, Miscellanea Zoologica Sumatrana 1, pp. 1-23 : 20

** 163. Onychogomphus geometricus perplexus subsp. n. ( fig. 2 ). -

Eastcoast Gvt.: 1 ♂. Deli. J. B. Corporaal leg. Holotype in the author's collection (Mus. Amsterdam ). Smaller and of slenderer build than typical geometricus from Java. Head and dorsum of synthorax coloured as in the typical race: the isolated yellow antehumeral spot larger. Sides of the thorax with the yellow predominating. so much so. that the sutures only are striped with, black; the entire metepimerum yellow, without posterior black margin. Legs with anterior femora broadly yellow interioriy. Abdomen with the black predominating: median yellow spot on segm. 2-4 isolated. much reduced in size. Basal yellow rings of segm. 3-6 occupying about 1/ 7-1/6 of the length of segments and entirely divided by the black on mid-dorsum. so as to form paired spots; 8-10 black. Anal apps. yellow. sligtly slenderer and longer than in geometricus: branches of app. inf. more strongly bent at base. Length: abd. +, app. 35. hw. 27. pt. 3 mm.

This is possibly the same species as Fraser's geometricus from Takengon (At jeh Gvt.) and considered by him a s a local race of that species (Mem. Mus. Roy. His. Nat.. hors serie. -4, 1932). Both agree in having the yellow predominating on the thoracic sides. but much reduced on the abdominal segments. In Fraser's ♂ the inf. app. is said by him to be black. although further in the text the author remarks that it is not different in colour from geometricus This new subspecies is undoubtedly closely allied to geometric us Selys. from Java. of which it may be regarded as a subspecies. As will appear from our sketches. the genitalia and apps. are almost exactly identical in the two races. but the colour-differences are very striking. The amount of variability in the colour-pattern of typical geometricus has been discussed in an earlier paper ( Lieftinck. Tijdschr. Ent. 72. 1929). - Among other characters. O. saundersi Selys differs by the black-tipped sup. apps.. by the different shape of the genital hamule. and by the absence of any dorsal interior projections of the inf. app. In O. duaricus . Fraser. the anterior genital hamule is in the form of a long tapering black spine. the branches of the inferior anal app. bear a strongly pointed basal tooth. and the distal 1 /3 of the upper appendages are black in colour.

Figures

Fig. 2.- Onychogomphus geometricus perplexus. ssp. n. ♂ Deli. Genitalia. left side. and anal apps .. right sight and dorsal view.