Body (Fig. 23) elongate-oval, moderately convex, black and shiny. Forehead (Fig. 24) strongly, longitudinally concave, with some coarser punctures medially. Frontal stria complete, carinate, feebly and inwardly bent at middle. Epistoma concave, moderately punctured. Labrum transverse. Mandibles long, convex, distinctly punctured. Antennae as colored as body, funiculus solid, enlarging gradually towards the club. Club large and oval, tomentose, with two transverse sutures.

Pronotum transverse, rounded and narrowed anterad. Marginal stria complete, a little crenate behind head. Lateral stria present medially only, shortened a both ends. Sides between lateral and marginal stria concave. Pronotal surface sparsely and finely punctulate, more coarsely at middle. Epipleura covered with yellowish-brown and short pilosity.

Elytra about twice as long as pronotal length, finely punctulate. Elytral apex with some coarser punctures and a feeble transverse impression. Dorsal striae distinct, impressed, especially the external ones and feebly crenate, 1 - 5 complete. Sutural stria complete, joining angularly with the 5th one at base. Humeral stria very fine and indistinct, present on basal 1/4. External subhumeral stria incised, present on basal half only. Epipleura concave at apex, tristriate. Marginal epipleural stria reaching to apex, abbreviated basally and replaced by a second stria, very incised and widened here. Marginal elytral stria present on apical 2/3, strongly incised and enlarged and with a row of punctures at bottom.

Propygidium (Fig. 25) rather long, convex, shallowly impressed at sides, covered with double punctation, consisting with large, ocelloid and oval punctures, intermingled with the small ones. The punctation becoming gradually denser and denser towards propygidial apex (0.2 - 0.5). Pygidium as punctured as pygidial apex, more finely apically, the dense and coarse pro- and pygidial punctation opaque.

Prosternal lobe (Fig. 26) rounded at apex, distinctly but moderately densely punctate, its marginal stria well impressed and complete. Prosternal keel finely punctulate, rounded at base. Carinal striae thin but distinct, divergent on basal 1/4 and then parallel, with a tendency to join basally. Lateral prosternal striae complete and carinate.

Anterior margin of mesosternum nearly straight, its marginal stria complete and subcariniform. Mesosternum very finely and sparsely punctulate. Meso-metasternal suture as well as median line of metasternum very fine. Lateral stria of metasternum extending obliquely and posteriorly, united with oblique stria that extends inwards from the middle of metasternal-metepisternal suture. Intercoxal disc of metasternum sparsely clothed with fine punctures. Lateral disc of metasternum densely covered with semicircular punctures.

Intercoxal disc of 1st abdominal sternum striate on each side and with an irregular row of round punctures at apex, densely distributed.

Legs distinctly dilated, the meso- and metatibia truncate at apex. Protibia with 10-12 fine spiny dents on outer margin. Tarsal groove slightly Sshaped, well defined ventrally. Meso- and metatibia with two rows of spinules on outer margin.

Male genital structure as figured (Figs. 27- 32).

Length.PE: 4.8 - 5.0 mm; total: 7.4 - 7.6 mm.Width: 4.0 - 4.1 mm.

Holotype: a male, Laos, Bolikhamsai pr., Ban Nape, 7.-16.2006, 18 o 20˙ N, 105 o E, E. Jendek & O. Sausa leg, [CHTL].

Paratypes: 7 specimens of both sexes, same locality, collectors and data, [CHTL]. 2 of them in the author˙s collection [CHSM].

It may be distinguished from other species of the genus as keyed below.

Key to species of Nagelius Lewis, 1909

1. Sutural stria abbreviated basally, not united with the 5th dorsal stria. Sri Lanka......................................................................................................................................................... N. castelnaudi (Marseul, 1870).

-. Sutural stria complete, united with 5th dorsal stria at base..................................................................2.

2. Upper side finely punctulate. Body length over 6.0 mm. Laos......................... N. turgidulus sp. nov.

-. Upper surface distinctly punctured. Body length under 5.5 mm............................................................3.

3. Propygidium less densely punctured as pygidium, shiny. Indonesia: Borneo....................................................................................................................................................... N. carinicollis (Lewis, 1893).

-. Propygidium as densely punctured as pygidium, opaque. India: Assam................................................................................................................................................................................ N. limatulus (Lewis, 1892).