Enghoffosoma digitatum Nguyen & Golovatch, 2016, sp. nov.
Creators: name: Nguyen, Anh D.
name: Golovatch, Sergei I.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polydesmida
Paradoxosomatidae
Enghoffosoma
Enghoffosoma digitatum

description: Enghoffosoma digitatum sp. nov.
(Figs 12–14)
Material examined. Holotype male (IEBR-Myr-107H), Vietnam, Dong Nai Prov., Cat Tien National Park, forest, 23–26 September 2004, leg. Anh Duc Nguyen. Paratypes: 3 males, 1 female (IEBR-Myr-107P), same data as holotype.
Diagnosis. The species is recognized by the paraterga being well developed; the gonopod postfemoral region consisting only of two processes: a thick, finger-shaped solenomere and a large, short, obscure, tuberculiform process e.
Name. “ digitatum ”, an adjective in neuter gender to emphasize the finger-shaped solenomere.
Description. Body length about 35.2–37.1 mm (male), 41 mm (female); width of midbody pro- and metazonae 2.9–3.0 mm (male), 3.7 mm (female) and 3.9–4.0 mm (male), 4.5 mm (female), respectively. Holotype length about 37.1 mm; width of pro- and metazonae ca. 3.0 and 4.0 mm, respectively. Body uniformly castaneous brown except for yellow paraterga and sterna.
Clypeolabral region densely setose. Epicranial suture thin, line-shaped, distinct. Antennae short, claviform, nearly reaching to the end of segment 3 if stretched laterally. In length, antennomere 2=3=4=5=6>7>1 (Figs 12 A– B).
Collum nearly semi-circular; surface shining and smooth, with at least two rows of 3+3 and 3+3 setae. Paraterga broadly triangular, without lateral incisions.
In width, segment 3<4<head<collum=2=5–17, thereafter body tapering towards telson. Prozonae and sides below pataterga finely shagreened. Metazonae shining, with a row of 3+3 on fore halves. Metatergal transverse sulcus thin, line-shaped, starting with segment 4, but completely developed, reaching to base of paraterga on segments 5–19. Pleurosternal carinae well-developed, ridge-shaped, with a caudal acute denticle on segments 2– 10, reduced to a caudal acute denticle on segments 11–17, thereafter completely missing. Stricture between pro- and metazonae shallow, clearly striolate at bottom. Axial line thin and distinct.
Paraterga (Figs 12 D–F) well developed, largely horizonal, only caudolateral corners somewhat upturned, but still lying below dorsum. Paraterga of segment 2 flabelliform, other paraterga subtriangular with a broadly rounded fore corner. Caudolateral corner acute, produced behind rear tergal margin into a small pointed tubercle in caudalmost segments (Fig. 12 F). Calluses thin, but more obvious on pore-bearing paraterga, without lateral incisions.
Epiproct (Figs 12 G–I) long, broadly truncated, without terminal tubercles. Tip not concave, with four spinnerets. Hypoproct broadly triangular, with two small, distolateral, setiferous knobs (Figs 12 H–I).
Sterna densely setose; cross-impression distinct, with a small cone caudally near each coxa, rear cones being somewhat larger than fore ones. Male sternum 5 with a large, densely setose, trapeziform process between coxae 4 (Fig. 12 C).
Legs (Fig. 12 E) about 1.4–1.5 times as long as midbody height (male). Male prefemora swollen dorsally. Femora without modifications. Tarsal brushes present until male leg 10, thereafter gradually thinning out.
Gonopod (Figs 13–14) relatively simple. Coxite large and stout, about half as long as femorite; distoventral part sparsely setose. Prefemorite densely setose, separated laterally from femorite by a subtransverse sulcus. Femorite suberect, subcylindrical, long, weakly constricted at 2/3 of its extent, with neither processes nor other modifications. Postfemoral region consisting only of a solenomere and a process e, clearly separated from femorite by a cingulum. Solenomere very thick, oblique, finger-shaped, pointed at tip. Process e large, obtuse, tuberculiform, slightly shorter than solenomere, somewhat curved ventrad. Seminal groove running distodorsad entirely mesally along femorite before entering onto a thick solenomere.
Remarks. The new species is fairly similar to E. bispinum Likhitrakarn, Golovatch & Panha, 2014, from Rayong Province, Thailand, in the gonopod postfemoral region consisting only of a solenomere and a process e. However, E. bispinum differs in the gonopod femorite being slightly curved, the solenomere with a small process terminating the seminal groove in the distal part, and process e being pointed, erect, slightly shorter than the solenomere.
description: Published as part of Nguyen, Anh D. & Golovatch, Sergei I., 2016, The millipede genus Enghoffosoma Golovatch, 1993 recorded in Vietnam for the first time, with descriptions of three new species (Diplopoda, Polydesmida, Paradoxosomatidae), pp. 151-166 in Zootaxa 4139 (2) on pages 162-165, DOI: 10.11646/zootaxa.4139.2.1, http://zenodo.org/record/265016