Baconia gounellei (Marseul, 1887)

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini), ZooKeys 343, pp. 1-297 : 28-29

Baconia gounellei (Marseul, 1887) Figs 3 E–FMap 1

Phelister gounellei Marseul, 1887: cxviii; Baconia gounellei : Lewis 1901: 372.

Type locality.

BRAZIL: Minas Gerais: Caraça [exact locality uncertain].

Type material.

Lectotype, probably female, here designated (BMNH): “Caraça (Minas Geraez) Bresil E.Gounelle 1.2.1885" / "Phelister Gounellei n.sp." / “Marseul’s Type." / "George Lewis Coll. B.M.1926-369" / "LECTOTYPE Phelister gounellei Marseul, M.S.Caterino & A.K.Tishechkin des. 2010". This species was described from an unspecified number of specimens, and the lectotype designation fixes primary type status on the only known specimen.

Diagnostic description.

Length: [not measured, ~2.5mm], width: [not measured, ~1.5mm]; body broadly subquadrate, sides weakly rounded, widest at humeri, strongly flattened, glabrous; dorsum entirely metallic blue, pronotum and pygidia slightly more greenish-blue; frons slightly depressed at middle, interocular margins weakly convergent dorsad, disk with few coarse punctures at middle, frontal stria present along inner margin of eye, bent mediad at front but broadly interrupted medially; epistoma with apical margin weakly emarginate; labrum about 3 ×wider than long; pronotal sides converging, arcuate to apex, weakly explanate at sides, lateral marginal stria complete around lateral and anterior margins, fine and close to margin, submarginal stria absent; pronotal disk with only fine ground punctation over median three-fourths of disk, with small, shallowly impressed secondary punctures sparsely interspersed at sides and front; elytra with single complete epipleural stria, outer subhumeral stria absent, inner subhumeral stria present as separate basal and median fragments, dorsal striae 1-2 more or less complete, 3rd stria slightly abbreviated at both ends, 4th and 5th striae represented by few apical fragments, sutural stria absent; elytral disk with small secondary punctures in apical fourth; prosternal keel broad, flat, base weakly produced, carinal striae more or less complete, separate, subparallel; prosternal lobe about two-thirds keel length, apical margin broadly rounded, marginal stria well impressed at middle, obsolete at sides; mesoventrite broadly and shallowly emarginate, marginal stria broadly interrupted at middle, reduced to lateral strioles; mesometaventral stria present at middle, arched strongly forward to near margin, inner lateral metaventral stria sinuately curving posterolaterally toward mesepisternum, abbreviated apically, outer lateral metaventral stria absent, metaventral disk impunctate at middle; protibia rather narrow, elongate, with three weak marginal teeth, outer margin very finely serrulate between; meso- and metatibiae narrow, mesotibia with a single marginal spine, metatibial margin smooth; pygidia short and wide, propygidium with complete basal transverse stria, discal punctures ocellate, medium-sized, separated by a little more than their diameters; pygidial punctures smaller, sparser toward apex. Male genitalia: not known.

Remarks.

Because Baconia gounellei is known only from the type specimen, which is in relatively poor condition, it is hard to adequately characterize. It appears very close to Baconia loricata , but is much smaller and not as flat. Among the highly flattened, metallic species, it is unusual in the presence of the 5th elytral stria, and further distinguished by the presence of fragments of the frontal stria across the anterior margin of the frons. The only other species in this group with the 5th elytral stria present, Baconia nebulosa , is completely lacking anterior fragments of the frontal stria, and has very short, unusual mandibles.