Review of the millipede genus Kronopolites Attems, 1914 (Diplopoda, Polydesmida, Paradoxosomatidae), with the description of a new species from Laos

Abstract The millipede genus Kronopolites currently comprises 11 species, including a new species from northern Laos: Kronopolites lunatus sp. n. The generic diagnosis is updated, a key given to all known species, and their distributions are mapped.

The present study treats some new material collected in Laos during several field trips. Prompted by the discovery of a new species, the authors have revised the entire genus Kronopolites adding a new diagnosis and updating both the catalogue and key to species. In addition, its distribution is mapped.

Material and methods
Material was collected in northern Laos in 2014 by SP and members of the Animal Systematics Research Unit, Chulalongkorn University. Specimens were preserved in 75% ethanol, and morphological investigations were carried out in the laboratory using an Olympus stereomicroscope. Scanning electron micrographs (SEM) of gonopods coated with gold were taken using a SEM JEOL JSM-5410 LV microscope. The gonopods were then removed from stubs and returned to alcohol after examination. Digital images of freshly fixed specimens were taken in the laboratory and assembled using the "Cell D " automontage software of the Olympus Soft Imaging Solution package. In addition, line drawings of gonopod characters were also prepared. The types are housed in the Museum of Zoology, Chulalongkorn University (CUMZ), Bangkok, Thailand.
Collecting sites were located by GPS using the WGS84 datum.
In the catalogue sections, D stands for the original description, subsequent descriptive notes or appearance in a key, R for a subsequent record or records, and M for a mere mention. Diagnosis. Body medium-sized to large (ca 23-42 mm long, ca 1.6-6.5 mm wide), with 20 segments. Paraterga from poorly to strongly developed, mostly without lateral incisions. Transverse metatergal sulcus distinct. Sterna usually modified, an acute cone often present near each coxa. Sternal lobe or cone(s) between ♂ coxae 4 present or absent. Pleurosternal carinae usually well-developed.
Gonopods rather simple to relatively complex; coxites elongate, subcylindrical, distoventrally sparsely setose, without tubercles; prefemoral (= setose) part of telopodite moderate to relatively large, 1/3-1/2 as long as acropodite; femorite rather slender to stout, slightly curved, enlarged distad, with an evident groove on mesal face and a distinct distolateral sulcus demarcating a postfemoral part; the latter typically carrying a fork consisting of two lateral/ventral processes: usually a smaller basal process b with its tip pointed basad to prefemoral part, and a larger, normally suberect or ventrally curved process a; solenophore strongly developed, slender, slightly longer than or nearly as long as femorite, strongly curved mesad, sometimes with a membranous, distally strongly expanded end, almost completely sheathing a flagelliform and longer solenomere; seminal groove running entirely or mostly mesally along an excavate femorite, then directed slightly dorsad in distal part of femorite to follow onto solenomere thereafter.
Remarks. Pocock (1895) described the type species in Strongylosoma Brandt, 1833, from a single female from Chee Foo, China. Soon after that Brölemann (1896), having received a male of this species from Chou-San Island, China, gave a more de-1936); Pei-shui-ho, 700 m a.s.l., northeastern Sichuan and southern Gansu (Attems 1937); Wenchow (= Yung-chia), Chekiang Province; Chekiang Province (Chamberlin and Wang 1953), Hangchow, Chekiang Province (Hoffman 1963 Name. To emphasize the lateral crescent-shaped processes on the gonopod. Diagnosis. Superficially very similar to K. acuminatus, but differs in the smaller size, the width of midbody pro-and metazonae being 2.4-2.5 and 3.1-3.2 mm, respectively (versus 4.5 mm and 6.5 mm, respectively); tarsal brushes are present until ♂ leg 9 (versus absent), and gonopod process b is > 2 times as long as process a (versus shorter), process a being clearly curved (versus nearly straight) while process b is enlarged and lies adjacent to the femorite (versus clearly separated from the femorite). Eventually, it keys out closest to K. formosanus (see Key below).
Live coloration mostly dark, blackish brown; antennae and head dark brown to light brown, venter and a few basal podomeres light brown to yellow-brown; coloration of alcohol material after four months of preservation faded to dark brown; antennae and epiproct light brown to light yellow, venter and a few basal podomeres light brown to pallid (Fig. 1A-I).

Conclusions
To date, 11 species have formally been described in Kronopolites, mostly found in China (5 species) and northern Vietnam (2 species). Only a single species each has been reported from northwestern India, northern Thailand, northern Taiwan and northern Laos (Fig. 4). There is little doubt that many more Kronopolites species are to be found in the future.