Denticulobasis and Tuberculobasis, new genera close to Leptobasis, with description of ten new species (Odonata: Coenagrionidae). Author Machado, Angelo B. M. text Zootaxa 2009 2108 1 36 journal article 10.5281/zenodo.187806 9a495f32-3eb8-4b35-bd46-adca3b5db2d2 1175-5326 187806 Tuberculobasis williamsoni sp. nov. Figures 2 b, 33–34, 52, 72–74, 93, 98. Etymology: Named after Edward Bruce Williamson, whose odonatological expeditions to Colombia and Venezuela yielded this species and an enormous number of valuable odonata specimens. Type specimens: Holotype (3) and allotype (Ƥ): COLOMBIA , Fundación, State of Magdalena, 11-I- 1917 , J.H. & E.B. Williamson leg. ( UMMZ ). Paratypes : 3 3 and 5 Ƥ: same data as holotype (three paratypes were collected along a stream in a shaded area); 1 3, 2 Ƥ: El Banco, State of Magdalena, 21-I-1917 , J.H. & E.B. Williamson leg.; 1 3, 2 Ƥ: VENEZUELA , Zulia State, Encontrados, 20-IV-1920 , J.M., E.B. Williamson & D.H. Ditzleri leg; 1 3: San Felipe, 20-III-1920 , J.M., E.B. Williamson & D.H. Ditzleri leg.. 3 3 and 7 Ƥ paratypes ( UMMZ ), 1 3 and 1 Ƥ paratypes ( MNRJ ); 1 3 and 1 Ƥ (A. B.M.M), 1 3 and 1 Ƥ (R.W.G.). Description . Male holotype . Head . Labium yellowish white. Labrum yellow; genae grey, base of mandibles, anteclypeus, postclypeus, antefrons, and top of head brown. Postocular lobes light orange with grey postocular spots. Rear of head yellowish white. Thorax. Prothorax: Anterior lobe grey, median and posterior lobes brown. Propleuron yellowish brown. Pterothorax (as Fig. 101 b) brown with greyish stripes on mesepisternum and metepisternum. Legs yellowish brown, wings hyaline, venation and pterostigma brown. Px in FW 11 (10%), 12 (90%); in HW 9 (30%), 10 (40%), 11 (30%). R 3 in FW arising near Px 5 (20%) and 6 (80%), in HW at Px 4 (10%), 5 (80%), 6 (10%). Petiolation distal to Ac by a distance equal (60%) or ½ (40%) of its length in FW, equal (30%) or ½ (70%) in HW. Abdomen. S1–2 brownish yellow with a lateral grey stripe. S2 with a square yellow dorsal spot at distal 1/4. S3–5 dorsally yellowish brown, laterally yellowish with brown distal rings; S6 brown, S7–10 yellowish brown. Cercus brownish yellow with dorso-lateral border dark brown; paraproct brownish. Structural characters . Hind lobe of prothorax ( Figs 33, 34 ) with median lobe semicircular and projected caudally; lateral lobes very small. Borders of median lobe two-lipped; dorsal lip upraised. Mesepisternal tubercles high (1.58 mm) in dorsal view strongly divergent ( Fig. 33 ), conical, directed antero-laterally, with bases adjacent to mid-dorsal carina ( Fig. 33 ). Cercus 1/2 shorter than paraproct ( Figs. 72–73 ), in posterior view ( Fig. 74 ) with a dorso-lateral semilunar cavity limited by a denticulated dark brown border. Penis ( Fig. 93 ) as described for the genus. Dimensions (mm). Abdomen 32.0–34.4 (mean 32.6); HW 17.5–19.0 (mean 18.2). Description. Female allotype. Color of head, thorax, and abdomen as described for male. Px in FW 12 (30%), 13 (60%), 14 (10%), in HW 10 (40%), 11 (30%), 12 (30%). R 3 in FW originating near Px 6 (90%) or 5 (10%) in HW near Px 5 (80%) or 6 (20%). Petiolation in FW distal to Ac by a distance equal (14.2%) or ½ (71.5%) of its own length, in HW slightly distal (14.2%), equal (14.2%) or ½ (71.4%) its own length. Structural characters . Hind lobe of prothorax ( Fig. 52 ) slightly concave at middle with no definition of lateral lobes. Mesepisternal tubercles well-developed but low, connected with anterior margin of mesostigmal plate ( Fig. 52 ). Cercus conical ( Fig. 98 ). Ovipositor (excluding styli) not surpassing level of cercus tip ( Fig. 98 ). Dimensions (mm). Abdomen 31.0–32.1 (mean 31.5); HW 18.9–20.4 (mean 19.8). Remarks . By having male mesepisternal tubercles high with base adjacent to mid-dorsal carina, and male paraproct much longer than cercus, T. williamsoni belongs in the costalimai species group, together with T. arara , T. costalimai , T. guarani , and T. inversa . It can be separated from them by characters given in the keys.