Denticulobasis dunklei sp. nov.

Figures 2 a, 4, 5, 9, 12, 14, 16, 20, 21, 87.

Etymology: Named after my colleague Sidney W. Dunkle, who collected the specimens in Peru, in recognition of his important contributions to Odonatology.

Type specimens: Holotype (3) and allotype (Ƥ). PERU, Loreto Department. Explorama Lodge, 50 miles NE of Iquitos on Amazon River at the junction with Yanomano River (3º21´59´´S, 72º47´56´´W), 24- VIII-1989, S.W. Dunkley leg.(FSCA).

Description. Male holotype.

Head. Labium whitish yellow. Labrum, base of mandibles, and genae greyish brown. Anteclypeus, postclypeus, frons, antennae, and top of head brown with large blue postocular spots. Rear of head whitish yellow.

Thorax. Prothorax: Propleuron and anterior lobe light blue. Pronotum light brown. Pterothorax: mesopleuron dominantly yellowish brown. Horns and area between them black, except at their latero-basal region, which is bluish. Metepisternum yellowish brown and metepimeron yellowish white. Three blue stripes; antehumeral, metepisternal, and a poorly defined metepimeral. Legs yellow. Wings hyaline, venation brown, pterostigma brownish yellow surrounded by yellow. Px in FW 12–13 in HW 11. R3 arising near Px 6 in FW and 5 in HW. Petiolation distal to Ac by a distance 1.5 times length of Ac in FW and equal to it in HW.

Abdomen. S1 and S2 dorsally brown, laterally light blue. S3–6 dorsally brown, laterally yellow with black ring at distal 1/10. S7 dorsally reddish brown, laterally yellow with black ring at proximal ¼. S8–10 dorsally brownish yellow, laterally yellow. Cercus and paraproct brownish yellow.

Structural characters. Hind prothoracic lobe (Fig. 4) with lateral lobes minute, median lobe projecting caudally, subquadrangular and two-lipped; ventral lip continuous, and dorsal lip reduced to two flaps separated by an incision at mid-line. Mesepisternal horns in dorsal view (Fig. 4) strongly diverging, each tapering to a blunt tip, mostly smooth with a transversely ridged portion at distal 1/5. Cercus in dorsal view slightly wider at apex than at base (excluding distal lobe) (Fig. 12) with a whitish shallow subtriangular membranous depression at base (Fig. 12). In ventro-posterior view (Fig. 16) cercus is spoon-shaped, and continues apically as a distal lobe. A ventral transverse digitiform structure present at limit between main portion and distal lobe of cercus (Fig. 16) which is not visible in dorsal view (Fig. 12). Penis (Fig. 87) as described for the genus.

Dimensions (mm). Abdomen: 32.9; HW 18.82.