Cephennomicrus cordithorax (Scott)

Jałoszyński, Paweł, 2019, Review of Cephennomicrus and Pomphopsilla of the Seychelles (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4568 (2), pp. 357-371 : 359

Cephennomicrus cordithorax (Scott)

( Figs 1 , 8 , 14–15, 26–27, 38)

Neseuthia cordithorax Scott, 1922: 204 , pl. 19, fig. 2.

Cephennomicrus cordithorax (Scott) ; Jałoszyński, 2008: 32.

Type material. Holotype (labels in Fig. 38 ): ♂, originally mounted on thick cardboard bearing male symbol and number "17" handwritten in black ink, now re-mounted on modern mounting card, with eight labels: " Percy Sladen / Trust Exped. / Brit.Mus. / 1926-246" [white, printed], " Silhouette, 1908 / Seychelles Exp." [white, printed], " Neseuthia / cordithorax / TYPE. H.Scott / TYPE " [white, handwritten, with " TYPE " printed on a blue card and glued onto the white label], " cordithorax Scott / Cl. Besuchet / dét. X 1957 " [white, printed and handwritten], "Figured specimen" [red, printed], "Type" [white circle with red margin, printed], and " CEPHENNOMICRUS / cordithorax / ( Scott, 1922) / det. P. JAŁOSZYŃSKI, 2019" [white, printed] ( NHM).

Revised diagnosis. BL ~ 0.80 mm; frontal impression in male poorly defined, developed as punctate and setose area and posterolaterally, but not posteriorly, delimited by weakly raised angulate tubercles, vertex with a pair of large impressions; aedeagus with moderately slender ventral apical plate and pointed apex, flagellum in ventral view with proximal loop and submedian kink.

Redescription. Body of male ( Fig. 1 ) moderately stout, strongly convex, umber brown; setae on head, pronotum and elytra very short but well-visible. BL 0.83 mm.

Head ( Fig. 8 ) broadest at large, strongly convex and coarsely faceted eyes, HL 0.10 mm, HW 0.23 mm; frons with median flattening covered with punctures and setae denser than those on surrounding areas, not delimited posteriorly, flanked by two pairs of posterolateral angulate tubercles; frons with a pair of small tubercles each bearing a porous field, vertex confluent with frons, with a pair of large but shallow and diffuse impressions; supraantennal tubercles weakly elevated. Punctures on frontal flattening distinct, on sides of frons and vertex and on posterior portion of vertex indistinct, moderately dense, very small; setae on frontal flattening moderately dense, short and suberect, setae on sides of frons and vertex and along posterior margin of vertex sparse, short and recumbent, impressions on vertex asetose. Antennae slender, with indistinctly delimited trimerous club, AnL 0.33 mm, antennomeres I–II strongly elongate, III–VI and VIII–X each about as long as broad, VII slightly elongate, XI about as long as IX–X combined, about 1.8 × as long as broad.

Pronotum subtrapezoidal, broadest near anterior fourth; PL 0.25 mm, PW 0.33 mm; anterior and posterior margins weakly convex, sides rounded in anterior third and barely noticeably sinuate in posterior third; anterior corners broadly rounded, posterior corners strongly obtuse-angled and blunt; base with two lateral pairs of small but distinct pits, inner pair connected by a shallow transverse groove, additionally with a small but distinct median pit; lateral pronotal carinae not serrate. Punctures on pronotal disc dense but superficial and diffuse; setae short, moderately dense, recumbent.

Elytra oval, broadest near anterior third; EL 0.48 mm, EW 0.40 mm, EI 1.19; humeral calli distinct; apices separately rounded, subtriangular adscutellar area strongly and abruptly elevated. Punctures on elytra similar to those on pronotum but deeper and elytral surface appears finely shagreened; setae short, moderately dense, recumbent.

Legs moderately long and slender, unmodified.

Aedeagus (Figs 14–15) stout; AeL 0.15 mm; median lobe in ventral view with subtriangular, moderately elongate apical plate; flagellum (Figs 26–27) in ventral view with proximal loop and submedian kink; each paramere with thick apical and thin subapical seta.

Female. Unknown.

Distribution. Seychelles, Silhouette Island.

Remarks. This species was described on the basis of only one specimen ( Scott 1922). Cephennomicrus cordithorax differs from all remaining members of the typicus group in poorly defined frontal impression which takes a form of a median flattening, accompanied by a pair of posterior impressions (in C. politus the frontal impression is also poorly defined, but the vertex lacks impressions), and in the flagellum in ventral view with one large proximal loop and a submedian kink.

Figures

FIGURES 1–7. Habitus of Cephennomicrus cordithorax (1), C. cornutus (2), C. minor (3), C. perexiguus (4), C. politus (5), C. typicus (6), and Pomphopsilla crenata (7).

FIGURES 8–13. Head of males in dorsal (8‾12) and anterodorsal (13) views. Cephennomicrus cordithorax (8), C. cornutus (9), C. minor (10), C. politus (11), and C. typicus (12‾13).

FIGURES 38–44. Historical (Scott's and Besuchet's) set of labels of holotypes (38, 39, 42) and lectotypes (40, 41, 43, 44). Neseuthia cordithorax (38), N. cornuta (39), N. minor (40), N. perexigua (41), N. polita (42), N. typica (43), and N. crenata (44).