Delius Casey

Jałoszyński, Paweł, 2017, Status of Nearctic subgenera of Microscydmus revisited (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4358 (3) : -

Genus Delius Casey , stat. rest.

Delius Casey, 1897: 497 . Type species: Delius robustulus Casey, 1897 (monotypy). Reduced to subgenus of Microscydmus by Franz (1985).

Revised diagnosis. Head short, transverse, with occipital constriction broader than half HW; tempora and genae with bristles; eyes located closer to mandibular bases than to posterior margin of head; submentum subtriangular, with lateral sutures extending posteromesally from mesal margins of cardines to posterior tentorial pits; hypostomal ridges complete, connected with posterior tentorial pits; antennae with distinct but slender trimerous club; prothorax laterally and lateroventrally with bristles; pronotum broadest in front of middle, without marked anterior corners, with distinct posterior corners, lacking lateral and sublateral carinae, with two pairs of antebasal pits, inner pair connected by transverse groove and lateral pits very close to lateral pronotal margin; basisternal part of prosternum longer than coxal part; prosternum between procoxae with indistinct, weakly elevated carina; notosternal sutures complete; hypomeral ridges complete but developed only at procoxal cavities, anteriorly not reaching middle of prothorax; each elytron with one small and asetose basal fovea; mesoscutellum exposed in intact specimens; mesoventral intercoxal process carinate but weakly elevated, long, extending from anterior ridge nearly to posterior margins of mesocoxal cavities; mesoventrite anteriorly with a pair of shallow lateral impressions functioning as procoxal rests, impressions indistinctly separated at middle, each with sharply marked anterior margin, diffuse posterior margin and densely filled with setae; metaventral intercoxal process not separating metacoxae, short, subtriangular and deeply notched at middle; lateral corners of metacoxae separated from lateral metaventral margins by posterolateral lobes of metaventrite; aedeagus with symmetrical median lobe, asymmetrical endophallic structures and free parameres.

Redescription. Body small (BL <1 mm), slender, moderately convex; constrictions between head and pronotum and between pronotum and elytra deep; body covered with setae and thick bristles.

Head ( Figs 2 , 8, 11 ) transverse, subhexagonal. Vertex and frons confluent; occipital constriction distinctly broader than half HL; frons subtrapezoidal; frontoclypeal groove absent; antennal insertions moderately broadly separated; eyes located closer to mandibular bases than to posterior margin of head; tempora and genae moderately densely covered with thick and long bristles. Mouthparts in the studied specimen poorly visible; mandibles subtriangular, slender; mentum subtrapezoidal; labial palps short with elongate palpomeres II and III, narrowly separated; maxillary palps relatively short, palpomere III about twice as long as broad, palpomere III nearly half as long as III, with distal half slender; submentum subtriangular, with lateral sutures ( Fig. 11 ; lss); hypostomal ridges ( Fig. 11 ; hs) complete, extending from lateral margins of cardines posteromesally up to posterior tentorial pits. Posterior tentorial pits narrow, slot-like and located in front of transverse impression demarcating 'neck' region; gular plate broad, subtrapezoidal, with indistinct gular sutures. Antennae ( Fig. 2 ) moderately long, slender, with enlarged scape and pedicel and loosely assembled, distinctly delimited trimerous club.

Prothorax ( Figs 2 , 8, 11 ) with rounded and weakly convex pronotum, its anterior margin confluent with sides, so that anterior corners are not marked, posterior corners distinct, obtuse-angled, posterior margin indistinctly bisinuate; pronotal base with two pairs of small antebasal pits ( Fig. 8 ; abp), of which inner pair is connected by transverse groove and lateral pair is located very close to lateral pronotal margins and obscured by dense bristles. Basisternal part of prosternum ( Fig. 11 ; bst) relatively short; prosternum between procoxae with indistinct, weakly elevated carina; notosternal sutures ( Fig. 11 ; nss) complete; hypomeral ridges ( Fig. 11 ; hyr) complete but located entirely in adcoxal region of hypomera, where they demarcate short, elongate, unsculptured and asetose inner portions of hypomera. Position of procoxae indicates closed procoxal cavities.

Mesoscutellum exposed in intact beetle, subtriangular with rounded apex ( Fig. 8 ).

Mesoventrite with shallow anterolateral impressions functioning as procoxal rests ( Fig. 14 ; pcr), which are separated at middle; their anterior margins are relatively well defined, but posteriorly impressions gradually become shallower and their posterior margins are diffuse, impressions are densely filled with setae; mesoventral intercoxal process ( Fig. 14 ; msvp) carinate but weakly elevated, long, extending from anterior ridge nearly to posterior margins of mesocoxal cavities.

Metaventrite broadened posteriorly; metaventral intercoxal process ( Fig. 14 ; mtvp) short, subtriangular, deeply and narrowly notched at middle, not separating metacoxae.

Metacoxae ( Fig. 14 ) separated from lateral metaventral margins by broad, rounded posterolateral lobes of ventrite.

Elytra ( Fig. 2 ) oval, elongate; each with one small and asetose basal fovea ( Fig. 7 ; bef) located close to mesoscutellum.

Abdomen ( Fig. 14 ) shorter than metaventrite; suture between sternite VII and VIII barely discernible.

Legs ( Fig. 2 ) moderately long, with particularly short and robust tarsi.

Aedeagus ( Figs 16–17 ) with symmetrical, thin-walled median lobe, asymmetrical endophallic sclerites and free parameres.

Remarks. Delius belongs to a group of genera characterized by the lateral sutures of submentum, and consequently cannot be placed within Microscydmus , which does not have such sutures. To date, fifteen genera with the submentum demarcated laterally by sutures have been known; both Delius and Neladius (treated below) also belong in this group. Comparative notes are given below (only some characters are listed):

- Delius differs from Alloraphes Franz, 1980a in: a trimerous antennal club (antennae gradually thickened in Alloraphes ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Alloraphes ); tempora with bristles (lacking bristles in Alloraphes ); labial palps much shorter than mentum (longer than mentum in Alloraphes ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating 'neck' region in Alloraphes ); the basisternal part of prosternum slightly longer than the coxal part (only 1/4–1/5 as long as coxal part in Alloraphes ); the inner (adcoxal) part of hypomeron anteriorly not reaching anterior margin of the procoxal cavity (reaching nearly the anterior margin of prosternum in Alloraphes ); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (two pits, each close to the lateral pronotal margin, connected by a transverse groove in Alloraphes ); each elytron with one basal fovea (two foveae in Alloraphes ); mesoventral procoxal rests filled with setae and broadly separated at middle (asetose and narrowly separated in Alloraphes ); the mesoventral intercoxal process posteriorly fused with the metaventrite, lacking a well-defined posterior tip (with a posterior tip in Alloraphes ); the anterior metaventral process absent (present in Alloraphes ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Alloraphes ); the aedeagus with a diaphragm located ventrally (basally in Alloraphes );

- Delius differs from Austrostenichnus Franz, 1971 in: a trimerous antennal club (antennae gradually thickened in Austrostenichnus ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Austrostenichnus ); tempora with bristles (lacking bristles in Austrostenichnus ); labial palps much shorter than mentum (longer than mentum in Austrostenichnus ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Austrostenichnus ); the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Austrostenichnus ); hypomeral ridges present (absent in Austrostenichnus ); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (two pits, each close to the lateral pronotal margin, connected by a transverse groove in Austrostenichnus ); the mesoventral intercoxal process present (absent in Austrostenichnus ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Austrostenichnus );

- Delius differs from Leptoderoides Croissandeau, 1898 in: a trimerous antennal club (antennae gradually thickened in Leptoderoides); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Leptoderoides); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Leptoderoides); the basisternal part of prosternum slightly longer than the coxal part (much shorter than coxal part in Leptoderoides); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (only a transverse impression without pits in Leptoderoides); sublateral pronotal carinae absent (present in Leptoderoides); the mesoventral intercoxal process posteriorly fused with the metaventrite, lacking a well-defined posterior tip (with a distinct posterior tip in Leptoderoides); mesoventral procoxal rests densely setose (asetose in Leptoderoides); the anterior metaventral process absent (present in Leptoderoides); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Leptoderoides);

- Delius differs from Mexiconnus Jałoszyński, 2013a in: tempora with bristles (lacking bristles in Mexiconnus ); strongly elongate, slot-like posterior tentorial pits (nearly circular in Mexiconnus ); long hypostomal ridges reaching posterior tentorial pits (not reaching tentorial pits in Mexiconnus ); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (a distinct and long transverse groove slightly deepened at each end in Mexiconnus ); mesoventral procoxal rests densely setose (asetose in Mexiconnus ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Mexiconnus ); each elytron with one basal fovea (two vestigial foveae in Mexiconnus );

- Delius differs from Neladius in: tempora and sides of pronotum covered with long, thick bristles (only thin setae in Neladius ); the pronotal base with pits and a transverse groove ( Neladius lacks any antebasal structures); hypomeral ridges present only in the adcoxal region of each hypomeron, and consequently the inner part of hypomeron is much shorter than half the length of prosternum (in Neladius hypomeral ridges run from the anterior margin of prothorax, demarcating extremely narrow inner parts of hypomera, which are longer than the prosternum); mesocoxae separated by a carinate mesoventral intercoxal process (in Neladius area between mesocoxae lacking carina, distinctly concave);

- Delius differs from Neuraphes Thomson, 1859 in: a trimerous antennal club (antennae gradually thickened in Neuraphes ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Neuraphes ); tempora with bristles (lacking bristles in Neuraphes ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Neuraphes ); the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Neuraphes ); hypomeral ridges present (absent in Neuraphes ); pronotal lateral carinae absent (sides of pronotum developed as carinate edges in Neuraphes ); the pronotal base with pits and a short transverse groove not disrupted at middle (with a transverse impression disrupted at middle by a gap or a longitudinal wrinkle in Neuraphes ); the mesoventral intercoxal process posteriorly fused with the metaventrite, lacking a well-defined posterior tip (with a distinct posterior tip in Neuraphes ); each elytron with one very small and asetose basal fovea (one large fovea filled with setae in Neuraphes ); anterior metaventral process absent (present in Neuraphes ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Neuraphes );

- Delius differs from Obesoconnus Jałoszyński, 2014b in: a general body form, which is 'ant-like', i.e., with deep constrictions between the head and pronotum and between pronotum and elytra (very stout, compact body with shallow constrictions in Obesoconnus ); a trimerous antennal club (antennae gradually thickened in Obesoconnus ); a transverse head with distinct tempora, occipital constriction and small eyes widely separated from antennal cavities (head round, lacking tempora and occipital constriction, with very large eyes adjacent to antennal cavities in Obesoconnus ); hypostomal ridges posteriorly reaching posterior tentorial pits (not reaching pits in Obesoconnus ); the maxillary palpomere IV much longer than broad at base, slender (palpomere IV very stout, about as long as broad in Obesoconnus ); the prosternum about as long as half of prothorax, with its basisternal part longer than the coxal part (prosternum remarkably short in Obesoconnus , only about as long as 1/4 of prothorax, with vestigial basisternal part); hypomeral ridges developed in adcoxal region of each hypomeron, and consequently the inner part of hypomeron is much shorter than half the length of prosternum (ridges run from the anterior margin of prothorax, demarcating inner parts of hypomera which are longer than the prosternum in Obesoconnus ); the pronotum longer than wide, lacking lateral edges or carinae (pronotum much broader than long, with distinct lateral carinae in the posterior third in Obesoconnus ); mesoventral procoxal rests filled with setae (asetose in Obesoconnus ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Obesoconnus ); the aedeagus with a diaphragm located on its ventral wall (basally in Obesoconnus ); - Delius differs from Palaeoscydmaenus Franz, 1975 in: a trimerous antennal club (antennae gradually thickened in Palaeoscydmaenus ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Palaeoscydmaenus ); tempora and sides of pronotum with bristles (lacking bristles in Palaeoscydmaenus ); labial palps much shorter than mentum (longer than mentum in Palaeoscydmaenus ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Palaeoscydmaenus ); hypomeral ridges present (absent in Palaeoscydmaenus ); the pronotal base with pits (with a transverse groove, lacking pits in Palaeoscydmaenus ); mesocoxae separated by a carinate mesoventral intercoxal process (mesocoxae contiguous in Palaeoscydmaenus ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Palaeoscydmaenus );

- Delius differs from Rutaraphes Jałoszyński, 2015 in: a trimerous antennal club (antennae gradually thickened in Rutaraphes); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Rutaraphes); tempora and sides of pronotum with bristles (lacking bristles in Rutaraphes); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Rutaraphes); lateral sutures of submentum posteriorly separated (connected in Rutaraphes); hypostomal ridges reaching posterior tentorial pits (not reaching pits in Rutaraphes); the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Rutaraphes); hypomeral ridges present (absent in Rutaraphes); the prosternal process indistinct, diffuse (prosternal process carinate, sharply demarcated in Rutaraphes); lateral pronotal carinae absent (sides of pronotum in its posterior half developed as carinate edges in Rutaraphes); four antebasal pronotal pits and a short transverse groove connecting the inner pair of pits (four unconnected pits and a posteromedian tubercle in Rutaraphes); mesoventral procoxal rests filled with setae (asetose in Rutaraphes); metacoxae not separated, lateral halves of metaventral process shorter than 1/4 of metacoxal length (metacoxae distinctly separated by two very long spines posteriorly reaching nearly posterior margin of each metacoxa in Rutaraphes); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Rutaraphes); the aedeagus with parameres and with a ventral diaphragm (aedeagus lacking parameres and with diaphragm shifted to the subapical ventral region in Rutaraphes);

- Delius differs from Scydmaenilla King, 1864 in: a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Scydmaenilla ); tempora with bristles (lacking bristles in Scydmaenilla ); labial palps much shorter than mentum (longer than mentum in Scydmaenilla ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Scydmaenilla ); the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Scydmaenilla ); hypomeral ridges present (absent in Scydmaenilla ); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (two pits, each close to the lateral pronotal margin, connected by a transverse groove in Scydmaenilla ); the mesoventral intercoxal process carinate and posteriorly reaching posterior margins of mesocoxal cavities (process subtriangular and posteriorly reaching middle or slightly beyond middle of mesocoxal cavities in Scydmaenilla ); the anterior metaventral process absent (present in Scydmaenilla ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Scydmaenilla );

- Delius differs from Scydmoraphes Reitter, 1891 in: a trimerous antennal club (antennae gradually thickened in Scydmoraphes ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Scydmoraphes ); tempora with bristles (lacking bristles in Scydmoraphes ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Scydmoraphes ); the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Scydmoraphes ); hypomeral ridges developed only in the adcoxal region of each hypomeron, and consequently the inner part of hypomeron is much shorter than half the length of prosternum (ridges run from the anterior margin of prothorax, demarcating inner parts of hypomera, which are longer than the prosternum in Scydmoraphes ); lateral pronotal carinae absent (sides of pronotum developed as carinate edges in Scydmoraphes , at least in the posterior third); the pronotal base with pits and a very short transverse groove connecting the inner pair of pits (with a long transverse impression or groove, in some cases deepened at each end in Scydmoraphes ); the mesoventral intercoxal process posteriorly fused with the metaventrite, lacking a well-defined posterior tip (with a distinct posterior tip in Scydmoraphes ); the anterior metaventral process absent (present in Scydmoraphes ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Scydmoraphes );

- Delius differs from Siamites Franz, 1989 in: thick bristles distributed only on sides of the head and prothorax, not arranged in tufts (bristles not only on sides of head and prothorax, but also on vertex, basisternal part of prosternum, mesoventrite, along posterior margins of mesocoxal cavities and along posterior margin of each abdominal sternite, forming conspicuous tufts or rosettes in Siamites ); strongly elongate, longitudinal posterior tentorial pits (short, slightly transverse pits in Siamites ); lateral sutures of submentum posteriorly separated (connected in Siamites ; the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Siamites ); hypomeral ridges complete, anteriorly connected with notosternal sutures (ridges incomplete, anteriorly obliterated and not connected to notosternal sutures in Siamites ); the pronotum broadest in front of middle (broadest at base or shortly in front of base in Siamites ); lateral pronotal carinae absent (sides of pronotum developed as carinate edges in Siamites , at least in the posterior third); the pronotal base with pits and a very short transverse groove connecting the inner pair of pits (with a long transverse impression deepened at each end in Siamites ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Siamites ); - Delius differs from Stenichnaphes Franz, 1980b in: a trimerous antennal club (antennae gradually thickened in Stenichnaphes ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Stenichnaphes ); tempora with bristles (lacking bristles in Stenichnaphes ); labial palps much shorter than mentum (longer than mentum in Stenichnaphes ); strongly elongate, longitudinal posterior tentorial pits (pits short and oblique in relation to the long axis of head in Stenichnaphes ); the basisternal part of prosternum slightly longer than the coxal part (only about 1/4 as long as coxal part in Stenichnaphes ); hypomeral ridges present (absent in Stenichnaphes ); lateral pronotal carinae absent (lateral carinae, though blunt, present in the posterior half or third of pronotum in Stenichnaphes ); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (long transverse groove connecting one pair of lateral impressions in Stenichnaphes ); each elytron with one small but distinct basal fovea (two vestigial, barely discernible foveae in Stenichnaphes ); mesocoxae separated by a carinate mesoventral intercoxal process (intermesocoxal region in Stenichnaphes weakly convex, lacking carina); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Stenichnaphes ); - Delius differs from Stenichnodes Franz, 1966 in: a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Stenichnodes ); tempora with bristles (lacking bristles in Stenichnodes ); labial palps much shorter than mentum (longer than mentum in Stenichnodes ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Stenichnodes ); the basisternal part of prosternum slightly longer than the coxal part (shorter than coxal part in Stenichnodes ); the inner (adcoxal) part of each hypomeron anteriorly not reaching the anterior margin of procoxal cavity (reaching anterior margin of prosternum in Stenichnodes ); mesoventral procoxal rests filled with setae (asetose in Stenichnodes ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Stenichnodes ); the aedeagus with parameres and a ventral diaphragm (lacking parameres and with a basal diaphragm in Stenichnodes ); - Delius differs from Stenichnus Thomson, 1859 in: a trimerous antennal club (antennae gradually thickened in Stenichnus ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Stenichnus ); mandibles subtriangular (falciform and very slender in Stenichnus ); tempora with bristles (lacking bristles in Stenichnus ); labial palps much shorter than mentum (longer than mentum in Stenichnus ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Stenichnus ); the basisternal part of prosternum slightly longer than the coxal part (distinctly shorter than coxal part in Stenichnus ); hypomeral ridges present (absent in Stenichnus ); the mesoventral intercoxal process posteriorly fused with the metaventrite, lacking a well-defined posterior tip (with a distinct posterior tip in Stenichnus ); the anterior metaventral process absent (present in Stenichnus ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Stenichnus );

- Delius differs from Zeanichnus Jałoszyński, 2013b in: a trimerous antennal club (antennae with an indistinctly delimited tetramerous club or gradually thickened in Zeanichnus ); a transverse head with eyes located anteriorly (subtriangular, elongate head with eyes located posteriorly in Zeanichnus ); tempora with bristles (lacking bristles in Zeanichnus ); labial palps much shorter than mentum (longer than mentum in Zeanichnus ); exposed posterior tentorial pits (pits hidden in a narrow transverse groove demarcating the 'neck' region in Zeanichnus ); long hypostomal ridges reaching posterior tentorial pits (ridges short, not reaching posterior tentorial pits in Zeanichnus ); hypomeral ridges present (absent in Zeanichnus ); four antebasal pronotal pits, of which the inner pair is connected by a transverse groove (two pits, each close to the lateral pronotal margin, connected by a transverse groove in Zeanichnus ); the mesoventral intercoxal process carinate and posteriorly reaching posterior margins of mesocoxal cavities (subtriangular and posteriorly reaching middle of mesocoxal cavities in Zeanichnus ); the anterior metaventral process absent (present in Zeanichnus ); metacoxae laterally broadly separated from lateral metaventral margins by rounded posterolateral lobes of metaventrite projecting posteriorly (metacoxae laterally reaching lateral metaventral margins in Zeanichnus ).

Figures

FIGURES 1–6. Microscydmus (Opresus) misellus (LeConte) (1, 4); Delius robustulus Casey (2, 5); Neladius tenuis Casey (3, 6). Dorsalhabitus of lectotypes (1–3) and their historical sets of labels (4–6).

FIGURES 7–12. Microscydmus (Opresus) misellus (LeConte) (7, 10); Delius robustulus Casey (8, 11); Neladius tenuis Casey (9, 12). Head, pronotum and elytral bases in dorsal view (7–9); head, prothorax and anterior portion of pterothorax in ventral view (10–12). Abbreviations: abp, antebasal pit; bef, basal elytral fovea; bst, basisternal part of prosternum; hr, hypostomal ridge; hyr,hypomeral ridge; lss, lateral suture of submentum; nss, notosternal suture; pcr, procoxal rest.

FIGURES 13–15. Microscydmus (Opresus) misellus (LeConte) (13); Delius robustulus Casey (14); Neladius tenuis Casey (15); pterothorax and abdomen in ventral view. Abbreviations: msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; pcr, procoxal rest; pm, paramere; stVII–VIII, abdominal sternite VII–VIII.

FIGURES 16–19. Delius robustulus Casey (16–17); Neladius tenuis Casey (18–19). Aedeagus in ventral (16, 18) and lateral (17, 19) views.