Atractides marsus sp. nov.

(Fig. 1)

Type material. Holotype Ƥ, dissected and slide-mounted, France F135, dept. Cantal, Auvergne, River Le Mars at crossing with D12 upstream of Le Falgoux 1115 m a.s.l., 45° 07'616" N, 2° 38'623" E, 18.v.2005 Smit.

Diagnosis. (Only female known). Dorsal and ventrocaudal muscle attachments and excretory pore sclerotized; Vgl-1 fused to Vgl-2; I-L-5 and –6 little modified, S-1 and -2 short, homoiomorphic, inserting at the same level, apically knob-shaped; P-2 with a pointed distoventral projection; both ventral setae and sword seta of P- 4 in proximal segment half.

Description

Female. Dorsal integument striated; muscle attachments plates sclerotized: postoc, D-1 and Dgl-3 on an Lshaped platelet, D-2 separate, D-3 fused with Dgl-4; D-4 separate. Coxal field: L 231; Cx-III W 272; Cx-I+II mL 91, lL 188; mediocaudal margin of Cx-1+2 tongue-shaped, apodemes Cx-2 directed laterally; Genital field (Fig. 1A): L/W 144/134, pregen large and slender, gonopore very long, genital plate L 76, flanking the postgenital sclerite, L Ac 1-3: 28, 27, 21.

Palp (Figs. 1C–D): total L 296, dL: P-1, 25; P-2, 67-69; P-3, 67-69; P-4, 103; P-5, 32; L ratio P-2/P-4, 1.0; P-2 ventral margin straight, ending in a pointed ventrodistal protrusion, ventral margin of P-3 straight, ending in a pointed ventrodistal edge, P-4 ventral setae both in proximal part od segment (ventral margin divided by setae insertions into three concave sectors, ratio 1:1:3), both ventral seta insertions flanked by tubercular protrusions, sword seta on the level of distoventral seta.

I–L (Fig. 1E): I-L-5/–6 little modified, I-L-5 with subparallel dorsal and ventral margins, S-1 and -2 short, homoiomorphic, with knob-shaped tip, inserted side by side (no interspace visible in lateral view); I-L-6 nearly straight, with dorsal and ventral margins equally diverging distally; I-L-5 dL 106, vL 83, dL/vL ratio 1.28, HB 27, dL/HB 3.9, S-1 L 35, L/ W 9.2, S-2 L 35, L/ W 9.2, distance S-1-2 0, L ratio S-1/2 1.0; I-L-6 L 101, HB 23, L/HB ratio 4.4; L ratio I-L-5/6 1.05.

Discussion. The female from Le Mars River agrees with Atractides pumilus (Szalay, 1946), and A. ubinicus Tuzovskij, 1980 from many points of view: sclerotization of muscle attachments plates and excretory pore, fusion of Vgl-1+2, genital plates triangular in shape and located near posterior end of gonopore, I-L-5/6 little modified, S- 1 and S-2 short and stout, without interspace, ventral setae on P-4 flanked by distinct, apically truncated tubercles. Both species differ from A. marsus in shape of P-2 (ventrodistal protrusion not developed or little projecting) and P-4 (distoventral seta and sword seta located in distal part of the segment). Atractides pumilus differs furthermore in a stouter I-L-6 (L/HB ratio 4.1). These clearcut differences, together with the fact that in pumilus -like species no particular sexual dimorphism is to be expected, allows to introduce a new species based on this single female specimen.

A further female with similar morphology of I-L-6 (L/HB 4.3) and P-4 (both setal tubercles in proximal half) is found in coll. Angelier („ Megapus primitivus ƤTech, Arles s/Tech [Pyr.-or.], 11.VIII.1948, phreaticole“). It differs, however, from the species discussed here, in having Vgl-1/2 separated and excretory pore unsclerotized, and from the type of A. marsus also in the absence of a ventrodistal projection on P-2. This specimen belongs surely not to A. pumilus (syn. A. primitivus, see Gerecke 2003), but represents probably a further undescribed species. In view of the bad conservation (idiosoma squeezed, one palp broken), a description of this taxon is impossible before more material becomes available.

Etymology. Named after its occurrence in Le Mars River.

Distribution. France, known only from the type locality.