Sinella quadriseta sp. nov.

Figs 1–16

Types. Holotype: female on slide, New Caledonia: Lifou island, near Easo, elevation about 25 m, 18.x.2000, litter in secondary forest, Berlese extraction, Louis Deharveng & Anne Bedos leg. (sample NC00-013). Paratypes: 6 females on slides and 10 in alcohol, same data as holotype. Holotype and 10 paratypes (4 on slides and 6 in alcohol) in MNHN; 6 paratypes (2 on slides and 4 in alcohol) in NJAU.

Description. Body length up to 1.45 mm.

Ground colour pale yellow in alcohol. Reddish pigment on Ant. I and III, head, thorax and Abd. I–IV (Fig. 1). Most specimens slightly reddish or almost pale. Antenna about 2 times as long as cephalic diagonal. Antennal segments ratio as I:II:III:IV = 1:1.9:1.8:3.0. Rod-like S-chaetae absent on Ant. I and 2 dorsal on distal part of Ant. II. Ant. III organ with chaetae 2 and 3 rod-like, chaeta 8 stronger than others (Fig. 2). Lateral process of labial palp thicker than normal chaetae, with tip reaching beyond apex of labial papilla (Fig. 3). Labial base as mrel1l2, all smooth; r 0.45–0.6 times as long as chaeta m; chaetae X2 and X4 ciliate; chaeta X smooth; chaeta X3 absent (Fig. 4). Dorsal cephalic chaetotaxy with 5 sutural mac (S) and 3 mac in Gr. II (Fig. 5).

Trochanteral organ with 12–19 smooth spiny chaetae; 8–10 in arms and 4–9 between them (Fig. 6). Ungual basal paired teeth unequal, outer one large with tip reaching the distal tooth; distal unpaired tooth tiny. Unguiculus with a large outer tooth. Tenent hair pointed, subequal to unguiculus (Fig. 7). Abd. IV 4 times as long as Abd. III along dorsal midline. Ventral tube anteriorly with 5–7 ciliate chaetae on each side (Fig. 8); posteriorly with 10–14 smooth chaetae (Fig. 9); each lateral flap with 7 smooth chaetae (Fig. 10). Manubrial plaque with 2 pseudopores and 2 ciliate chaetae (Fig. 11). Distal smooth part of dens slightly shorter than mucro. Mucronal basal spine short with tip just reaching apex of subapical tooth (Fig. 12).

Th. II with 2 (m1, m 1i) medio-medial, 1 (m4) medio-lateral, and 15–17 posterior mac. Th. III with 18–19 central, 6 (m5, a6, a 6i, p6, m6, m6e) lateral mac, and 1 mes (p6pe) (Fig. 13). Abd. I with 4 (m 2i, m2–m4) central mac. Abd. II with 3 (a2, m3, m3e) central and 1 (m5) lateral mac. Abd. III with 1 (m3) central and 2 (pm6, p6) lateral mac (Fig. 14). Abd. IV with 4 (I, M, A5, B5) central, 6 (D3, E2–4, E2p, F1) lateral mac and at least 22 sens; E4 sometimes as mes; at least 6 sens much shorter than others (Fig. 15); pseudopore between I and A5. Abd. V with about 45 chaetae and 4 sens; m2, m3 and m5 always much larger than others (Fig. 16).

Ecology. In litter of secondary forest, in the doline of Easo cave.

Etymology. Named after its unusual pattern of 4 S-chaetae on Abd. V.

Remarks. This species is characterized by ciliate X2, X4 and smooth X on ventral side of the head, 2+2 mediomedial and 1+1 medio-lateral mac on Th. II, 4+4 mac on Abd. I, presence of mac a2 on Abd. II, 2+2 mac on Abd. III, 4+4 central mac on Abd. IV, and 4+4 sens on Abd. V. It is closest to S. claviseta sp. nov., but differs from it in claw structure, presence of mac m 2i on Abd. I and mac a2 on Abd. II, ventral tube chaetotaxy and shorter distal smooth part of dens (Table 1).