Paracortina yinae Liu & Tian

Liu, Weixin & Tian, Mingyi, 2015, Two new cave-dwelling species of the millipede genus Paracortina Wang & Zhang, 1993 from southern China (Diplopoda, Callipodida, Paracortinidae), ZooKeys 517, pp. 123-140 : 128-136

Taxon classification Animalia Callipodida Paracortinidae

Paracortina yinae Liu & Tian sp. n. Figs 23-28, 29, 30-33, 34-37, 38-41, 42-45

Material examined.

Holotype: adult male (SCAU), China, Guangxi, Baise City, Longlin County, Tianshengqiao Town, Yanchang Village, Cave I, 24.875732°N, 105.150143°E, 867 m, 12.VI.2014, leg. Mingyi Tian, Weixin Liu, Haomin Yin & Xiaozhu Luo. Paratypes. 2 males, 3 females, 2 juveniles (SCAU), same locality, together with holotype.

Description.

Length of adult males 39-52 mm, of adult females 47-55 mm. Width of midbody segments in adult males 2.2-2.6 mm, in adult females 2.5-3.0 mm. Body with 53-61 pleurotergites + telson. Holotype 44.0 mm long, 2.5 mm wide on midbody segments, maximum width on 6th pleurotergite 2.5 mm, body with 54 pleurotergites + telson. Body coloration yellow-brownish. Metazonae slightly darker than prozonae, posterior margin of pleurotergites dark brown to brownish, more evidently so on the anterior pleurotergites (Figs 23-29). Head brownish to chocolate brown, epicranial suture distinct, with a slightly smaller, median, beak-shaped process located between antennae in males, surface below the vertex and genae densely beset with brown granules and fine setae (Fig. 23). Genae, labrum, the edge between the dorsal and the frontal face of head marbled dark brown. Ocellaria composed of ca. 21-32, dark grey ocelli arranged in four irregular longitudinal rows. Tömösváry’s organs about 4 times larger than an ocellus, placed between ocellaria and base of antenna (Fig. 23). Antennae brownish, tip of each antennomere infuscate; very long, extending behind posterior edge of pleurotergite 6 (male) or 4 (female) when stretched backwards (Figs 23, 29), antennomere length ratios: 2=3>4=5>6>1>7, antennomeres 5 and 6 with a small distodorsal field of fine setae (Fig. 39). Legs yellow-brownish to dark brownish, distal parts of femora much darker.

Collum much narrower than head, with two paramedian spots covered with brown granules, pleurotergite 6 in males strongly enlarged. Prozonae delicately alveolate-areolate; fine longitudinal striations in front of stricture between pro- and metazonae. Two first primary crests on collum relatively large. All crests on the metazonae, ozopores site, pleurotergal setae, and axial line as in Paracortina zhangi sp. n. (Figs 24, 26, 28); setal pattern as in Table 1.

Male leg-pairs 1 and 2 much shorter, leg-pair 3 slightly shorter than following legs (Fig. 23). Midbody legs about 4 (male) or 3 times (female) as long as pleurotergal height, only tibia finely micropapillate ventrally (Fig. 38). Tarsi 1-3 only 1-segmented, from 4 to ultimate pair 2-segmented; tarsal pads present from leg-pairs 3 to about 15. All legs ending with a rather slender, long and curved claw (Figs 1, 2, 15). Coxal sacs present from leg 3 to at least 25, but most abrased. Coxa 2 with a small anterior process and a posterior gonopore, the latter placed on a small cone. Coxa 6 with a small, pointed posterior process (e) (Fig. 30). Coxa 7 with a long, subfalcate and api cally pointed posterior (f), and a very strong, rounded anterior process (t) (Fig. 31). Coxae of remaining legs normal. Epiproct simple, with 3+3 anterior and 8+8 posterior tuberculations in transverse rows. Hypoproct, anal valves and spinnerets as in Paracortina zhangi sp. n. (Fig. 27).

Gonopods (Figs 32-33, 40-41) yellow-brown to brown basally, seminal groove and telopodite black brown. Coxa with an anterior process (a) and a rather slender process (b), the latter about half the length of telopodite. Prefemur with a large, clavate process (c), densely covered with long macrosetae apically. Femoroidal stem long, slender, rather strongly curved, directed cephalad. Telopodite’s terminal part twisted, trifid, with a digitiform lateral (h), and a slender, apically pointed lobe (t). Solenomere (s) bifid, parasolenomere (ps) much shorter; seminal groove ending on the longer branch.

Female. A little larger than males, pleurotergites 2 and 3 strongly enlarged. Leg-pairs 1 and 3 with tarsal pads (Figs 34-35). Prefemur 3 evidently enlarged (Fig. 35). Leg-pair 2 (Fig. 36) rather strongly reduced down to a pairs of stout, apically deeply biramous remnants in adult females, normal in younger ones. Cyphopods small, densely setae, hidden in membranous sacs, partly extruded, laterally divided in the middle, the smaller part roundly concave apically (Figs 36-37). Coxae 6 and 7 normal, without processes.

Etymology.

The species is named in honour of Miss Haomin Yin, an active collector in our team.

Remarks.

The new species differs from its congeners by the presence of small, pointed, posterior processes (e) on coxae 6 and two pairs of processes on coxae 7 in males, as well as in certain specific charaters of the male gonopods and reduced leg-pair 2 in females.

Distribution.

China: Guangxi (Fig. 46).

Cave I (Figs 42-45) is situated at the foot of a karst mountain. It is a large cave, made up of a hall of several layers covered by numerous big rock boulders. We explored approximately 150 meters deep, but then had to withdraw because of a rushing underground river. Other animals also found in this cave are diplopods from the genera Glyphiulus ( Spirostreptida , Cambalopsidae ) and Eutrichodesmus ( Polydesmida , Haplodesmidae ), the blind trechine beetle Satotrechus longlinensis Deuve & Tian, 2011, and bats.