Orthomorphoides setosus (Attems, 1937) Attems, 1937

Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2011, Revision of the Southeast Asian millipede genus Orthomorpha Bollman, 1893, with the proposal of a new genus (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 131, pp. 1-161 : 106-110

Orthomorphoides setosus (Attems, 1937) comb. n. Figs 116117

Orthomorpha setosa Attems 1937: 71 (D).

Orthomorpha setosa - Attems 1938: 207 (D).

"Orthomorpha" setosa - Jeekel 1963: 267 (M); 1968: 56 (M).

Syntypes.

1 ♂, 1 ♀ (NHMW-3517), Vietnam, Lamdong Prov., Dalat, 1500 m, 02.1933, leg. C. Dawydoff.

Non-type.

1 ♂ (NHMW-7987), Vietnam, Lamdong Prov., Dalat, Peak Lang Biang, 1200-2400 m, no date, leg. C. Dawydoff, det. C. Attems. This sample was erroneously labeled as a syntype, which cannot be such, because only material from Dalat was referred to in the available descriptions ( Attems 1937, 1938).

Redescription.

Length ca 18 mm (♂) or 20 mm (♀), width of midbody pro- and metazona 2.0 and 2.5 mm (♂), 2.2 and 2.8 mm (♀), respectively.

Coloration of alcohol material after long-term preservation faded to uniformly light brown (Fig. 116) (vs castaneous brown to light brown, as given in the available descriptions ( Attems 1937, 1938)).

Clypeolabral region densely setose, vertex bare, epicranial suture distinct. Antennae short, poorly clavate (Fig. 116B), extending behind (♂) or not reaching end of segment 2 (♀) dorsally. Head in width <collum <segment 2 = 3 <4 <5-17 (♂, ♀); thereafter body gently and gradually tapering. Collum semi-lunar, with three transverse rows of setae traceable only as insertion points: 4(5)+4(5) anterior, 4+4 interm ediate and 4+4 posterior; surface very slightly rugulose near caudal margin; paraterga subrectangular, with a small lateral incision at caudal 1/3; caudal corner nearly pointed, narrowly rounded, not extending behind tergal margin (Fig. 116A & B). Tegument shining, prozona very finely shagreened, metaterga rugose to rugulose (especially well so in caudal halves of metaterga), finely granulate, below paraterga microgranulate. Postcollum metaterga with 3-4 transverse, often irregular rows of medium-sized, sometimes abraded setae always traceable at least as insertion points, short wrinkles or knobs: 5 –7+5– 7 in front row on minute knobs and 5 –6+5– 6 in second row (both pre-sulcus), as well as 6 –8+6– 8 in both subcaudal and caudal rows (both postsulcus ones) on wrinkles or knobs (Fig. 116A-G & J-L). Axial line rather clear, especially so on metaterga, starting from collum. Paraterga moderately strongly developed (Fig. 116A-G & J-L), nearly always spiniform and pointed, mostly subhorizontal, set low at about 1/2 midbody height, lying well below dorsum; shoulders strongly and regularly rounded, well-developed, caudal corners of postcollum paraterga always slightly extending beyond tergal margin. Calluses delimited by a sulcus only dorsally, narrow, with four small lateral incisions on callus 2 and three similarly unclear indentations on each following segment (Fig. 116A-F & J-L). Posterior edge of paraterga always evidently concave (Fig. 116E-G & L). Ozopores evident, lateral, lying in a deep ovoid groove at about 1/3-1/4 paratergal length in front of caudal corner. Transverse sulcus present on metaterga 5-18, complete and reaching bases of paraterga, incomplete and faint on metaterga 4 and 19 (♂, ♀), beaded at bottom, rather deep and (Fig. 116A, C, F & J-L). Stricture between pro- and metazona rather shallow, narrow, evidently beaded at bottom down to base of paraterga. Pleurosternal carinae poorly developed, especially so in ♀, as small, complete and roughly granulate crests with a distinct tooth both frontally and caudally only on segments 2 and 3, traceable as a small caudal denticle on segment 4, thereafter missing (♂, ♀) (Fig. 116B). Epiproct (Fig. 116E-G) conical, rather short, flattened dorsoventrally, with evident apical papillae directed caudally and with two very strong pre-apical papillae not very strongly removed from an emarginate tip. Hypoproct (Fig. 116G) semi-circular, setiferous knobs at caudal edge very small and moderately well separated.

Sterna sparsely setose; a large central lobe with a paramedian pair of evident, subcontiguous, anteroventrally directed, setose cones between ♂ coxae 4 (Fig. 116I & J); a pair of small paramedian tubercles in front of gonopod aperture. Legs short and slender, almost not incrassate in ♂, midbody ones ca 0.9-1.1 (♂) or 0.7-0.9 times (♀) as long as body height, prefemora without modifications, ♂ tarsal brushes present until legs of ♂ segment 9.

Gonopods (Fig. 117) simple. Coxa long and slender, without setae. Prefemoral part densely setose, more than 2 times shorter than femorite. The latter about as long as solenophore, slender, strongly curved, enlarged distad, without sulcus demarcating a postfemoral part. Solenophore tip clearly bifid, with a subterminal spine (s) and a terminal lobule; solenomere long and flagelliform, tip a little exposed.

Remarks.

Jeekel (1968) has long separated both Orthomorpha setosa Attems, 1937, from Vietnam, and Pratinus exaratus Attems, 1953, from Laos, as warranting a genus of their own. Now that we have been privileged to revise the type material of the former species, this issue is being formalized by proposing a new genus, Orthomorphoides gen. n., to incorporate both Orthomorpha setosus (Attems, 1937), comb. n., and Orthomorpha exaratus (Attems, 1953), comb. n.

Orthomorpha exaratus differs readily from Orthomorpha setosus as follows. Collum with paraterga spininform and extending behind tergal margin. Paraterga with only two lateral incisions. Three rows of setae on metaterga: one in front, the other two behind sulcus. Lobe between ♂ coxae 4 missing. Gonopod femorite slenderer. Type locality: Xieng Kuang Park, Vientiane, Laos ( Attems 1953).