Arrenurus claviger Koenike, 1885 (219)

(Fig. 2, Tables 1, 2)

Arrenurus calycularis Georgévitsch, 1906 (143)

Material examined: Progeny from a ten females collected from a pool in a ploughed field near Trzebień, Dolice district, Poland, 53o17’N, 15o27’E, among reed­marshes, 1 May 1998.

Diagnosis: Dorsal plate egg­shaped with small anterior­lateral indentations, Lp2 and Mh1 bipectinate; median margins of CpI 1.5 times longer than the CpII median margins which are a little longer than CpIII margins; Expp pentagonal­shaped, its width equal to its length, Exp located anterior to the centre of Expp and above the E2 setae; IITi10 long, pectinate, and situated almost in the same place as IITi9, IIITa13 pectinate.

Description: The egg­shaped dorsal plate is widest in the middle of its length and narrows in the posterior part. The anterior margin is slightly convex and the posterior one is pointed. The anterior­lateral indentations are fairly small, with slightly obtuse angles, and reach to about one­fifth of the plate length and one­fifth of its width. Seta Lpl is tripartite, setae Lp2 and Mh1 are bipectinate, the remaining setae are smooth (Fig.2).

The median margins of CpI are 1.5 times longer than the CpII median margins which are a little longer than CpIII ones, the ratio is 1.5/1.1/1. Setae C1, C2, C3 and V3 are bipectinate, C4, Lh2 and Lh3 are pectinate and the remaining setae are smooth. The distance between the C4 seta and the CpIII median margin is 1.5 times longer than the distance between the C1 seta and CpI median margin (Table 1, Fig. 2).

The excretory pore plate is pentagonal­shaped, its width is equal to its length. The excretory pore is located anterior to the centre of the plate and above the E2 setae (Table 1, Fig. 2).

The pedipalps are typical for Arrenurus species. Seta PIII1 is bipectinate, PIV1 and PV6 are fairly thin and PV8 is fairly long (Table 1, Fig. 2). The first segment of the chelicerae is bottle­shaped, with one margin flat and the other hook­like (Fig. 2).

The proportions of segments are more or less the same on each limb. The shortest segment, the trochanter, constitutes about 2/3 of the femur and genu which are of the same length; the tibia is 1.5 times longer and the tarsus 2 times longer (Table 2). Seta ITi8 is thin and long, IITi10 is long, pectinate, and situated almost in the same place as IITi9. Setae IIIGe2, IIITi7 and IIITi8 are fairly long and bipectinate (Fig. 2).