Amphicnemis amabilis, M.A. Lieftinck, 1940

M. A. Lieftinck, 1940, Descriptions and records of South-East Asiatic Odonata (II), Treubia 17 (4), pp. 337-392 : 368-370

Amphicnemis amabilis , sp. n. ( fig. 15 , pl. 15 fig. 2 ).

Material studied: — 13 ♂, 11 ♀ (mostly ad.), E. Borneo, N. Koetai, Sangkoelirang distr., Kariorang, Pelawan Besar, Batau Besi & Maloewi , April- June, 1937, M. E. WALSH leg., in the Buitenzorg Museum. Holotype ♂ and allotype ♀, Kariorang , April1937. Male (ad). - Labium Maize -yellow. Labrum shining black with broad citron-yellow margin. Mandible-bases, genae, and anteclypeus bright greenish-yellow, as is also an isolated curved stripe in front of frons. Anteclypeus with two black spots, postclypeus wholly shining black. The rest of the head bronze-green above. Antennae brown, first two joints with a bluish spot, third joint with yellow anterior streak. Rear of the head black; a pale blue stripe along the eye-margin, tapering to a point posteriorly.

M. A. LIEFTINCKI Descriptions and records of S. E. Asiatig Odonata; 369

Prothorax cream-coloured; anterior lobe finely bordered with black; dorsum with a trapezoidal bronzy-green mark traversing the length of the mid-lobe, narrowing to a longitudinal streak against anterior lobe, and broadening suddenly to a transverse, crescent-shaped spot covering the middle one-third of the posterior lobe. Seen from above, the lateral angles of the posterior margin “ m DPOCIUOP-fl n little, but in side-view they are cut off under right angles.

Synthorax above very brilliant metallic blue-green; mesepimeral (juxta-humeral) lustrous spot, and dorsal anastomosis along upper end of first lateral suture, slightly variable in extent, usually shaped as shown in fig. 15. Mesinfraepisternites; Sides and under surfaces bright yellow.

Coxae buff-yellow, femora light cadmium in full-coloured individuals, tibiae and tarsi paler; extremities of all femora and tibiae narrowly ringed with black; apices of tarsal joints and spines also black.

Wings hyaline. Pterostigma very oblique, but with parallel sides, bicolorous. In fore wing the costal and distal border (and the upper half of the proximal border as well) are bright yellow, the lower half of the proximal and the entire anal border being black in colour, whilst the blackish-brown centre occupies only the lower proximal portion of pt. In the hinder wings pt is blackish-brown, its margin yellow, most distinctly so along costal border, which, itself, is yellow or pale brownish, according to age and maturity. Postnodals 12-13/11-12. Abdomen long and slender. Segments 1 and 2 metallic-green above and with narrow black apical rings, clear yellow aside. The succeeding segments are dark metallic-brown, becoming progressively darker (black from 7 to 10); 3 - 7 with very narrow yellow anterior rings, interrupted mesially; sides and under surfaces yellow. Terminal segments rather inflated, deep black with slight metallic-green lustre, hind margin of 10 reddish-brown.

Anal appendages pure white, or pale yellow, shaped as shown on pl. 15 fig. 2 . Female (ad). - Closely similar to the male and differing only in that the prothorax and the sides of the synthorax are olive-buff or vinaceous-buff (discoloured?) in fully matured examples.

Pterostigmata less definitely bicolorous than in the male and Occasionally obscured so much as to present only a yellow costal border to the pt of fore wings. Neuration otherwise as in the opposite sex.

Abdomen coloured much as in the male, the yellow anterior rings enlarged, though interrupted mid-dorsally. Segments 8 and 9 each with an irregular yellow or bluish-green side-spot; 10 and anal appendages black Basal half of genital valves yellow, distal half black, tipped with yellow, projecting beyond apex of abdomen for about the length of segment 10.

370 TREUBIA DEEL 17, 1940, AFL. 4.

This new species is very closely allied to, if not identical with, A. bicolor (Martin) , from Banguey. A. ecornuta SELYS, from Sumatra, is also very similar; and these three species form a distinct section within the genus, characterized by the simple structure of the prothorax in both sexes, the bicolorous pterostigma, the reduction of the metallic-green marks on the dorsum of pro- and synthorax, and by the more compact build of the anal appendages. The males of all three species are peculiar for the presence of a strong spine on the upperside of the inferior appendages.

I have seen a number of undescribed species from- Celebes and the Philippines, which seem to fit this section of the genus more appropriately than the Malaysian species-groups of wallacei and martini .

Figures

Fig.15. Colour-pattern of synthoraxof Am- phicnemis ecornutaSelys, ♂ (Lampongres., left), andofA.amabilis, sp.n. ♂ (E.Borneo, right).

Pl . 15 . — Structural characters of Malaysian species of Amphicnemis . 1 - 3 . Male anal appendages , dorsal view and right side . 4 . Right lateral view of prothorax .

Fig. 2. Ventral aspect of seminal vesicle (top) and left side-view of anal appendages of Euphaea subnodalis Laid., from Mt. Marapok (bottom).