Tatocnemis, Kirby, 1889

Kirby, W. F., 1889, Descriptions of new Genera and Species of Odonata in the Collection of the British Museum, chiefly from Africa., Proceedings of the Zoological Society of London 1889, pp. 297-303 : 300-301

Genus Tatocnemis .

Male. Wings long and narrow, petiolated to the level of the arculus, with three concavities on the hind margin, between the subcostal radius and the lower sector of the arculus; fore wings with 24-28 and hind wings with 20-21 postnodal nervures; pterostigma broad, lozenge-shaped, covering 1½ or 2 cells. The median sector rises at or a little beyond the nodus, the subnodal sector from the second postnodal cross-nervure on the fore wings (exceptionalla from the first or third), and from the first on the hind wings; the nodal sector rises at the 9th to the 13th crossnervure (usually from the 10th) on the fore wings, and between the 6th and 8th on the hind wings; and the ultranodal sector rises from two to four (usually two) cross-nervures further. The first postcostal nervule is placed very little beyond the first antenodal cross-nervure. The arculus is angulated, and placed distinctly beyond the level of the second antenodal cross-nervure. The trapezium is about twice as long as broad; its basal side is shorter than its outer, which is oblique, and its upper side is shorter than its lower; there are from two to four cells (usually two) between the trapezium and the first transverse cross-nervuie from above; the lower sector of the trapezium rises on a level with the middle of the trapezium, and runs to the hind margin beyond the level of the origin of the ultranodal sector. Nodus placed at about one fourth of the length of the wing.

Abdomen long and slender, first joint very short, second about 2½ times as long as broad, 3rd 4 times longer than the second, the rest gradually shortening to the 7th; 8th about half as long as the 7th; 9th and 10th each about half as long as the preceding; upper anal appendages as long as the 9th segment, arched, with a large semicircular protuberance beneath; lower appendages very short.

Legs slender, not dilated, with long slender spines.

A very remarkable genus, most nearly allied to Priocnocnemis, Selys (= Hypocnemis , Selys, olim), from the Philippines, and Idiocnemis, Selys , from New Guinea, the only genera of Odonata known with emarginate wings. It differs abundantly from both in the extremely petiolated wings, the large pterostigma, and the different points of origin of the sectors