Forsteropsalis nigra ( Forster 1944 ) Taylor, 2011

Taylor, Christopher K., 2011, Revision of the genus Megalopsalis (Arachnida: Opiliones: Phalangioidea) in Australia and New Zealand and implications for phalangioid classification 2773, Zootaxa 2773 (1), pp. 1-65 : 58-59

Forsteropsalis nigra ( Forster 1944) new combination, new rank

( Figs 121–123 )

Megalopsalis chiltoni nigra Forster 1944: 186 .

Material examined. Male lectotype (here designated). WI. Feilding , New Zealand, 20 February 1943, R . Forster ( MONZ 2 /23) .

Other material examined. WI. 1 female, ditto, 23 Dec 1942 ( MONZ) .

Description. MALE (N = 1). Prosoma length 2.2, width 3.2. Prosoma (fig. 121) medium brown, propeltidium and mesopeltidium heavily denticulate. Ocularium medium brown, heavily denticulate. Opisthosoma medium brown with scattered orange lateral punctures. Coxae dark brown with orange spots; venter of opisthosoma medium brown with orange spots.

Chelicerae (fig. 122). Segment I 7.5, segment II 9.0. Medium brown, slender.

Pedipalps (fig. 123). Femur 1.8, patella 0.6, tibia 0.8, tarsus 2.4. White with brown stripe around base of femur; with ventral row of denticles on femur. Small pointed mediodistal apophysis on patella, median side of patella and tibia not especially setose. No tooth-comb on claw.

Legs. Leg I femur 7.0, patella 1.0, tibia 5.0; leg II femur 11.0, patella 1.5, tibia 10.0; leg III femur 6.0, patella 1.0, tibia 5.0; leg IV femur 8.5, patella 1.5, tibia 7.0. Medium brown. Femora denticulate; remaining segments unarmed. Tibia II with six or seven pseudosegments; tibia IV with two pseudosegments.

FEMALE (N = 1). Prosoma length 1.8, width 2.6. Dorsal prosomal plate mottled off-white and dark brown. Ocularium dark brown; few black setae not forming rows. Opisthosoma mottled grey-brown, few scattered black setae, scattered patches of off-white. Coxae dark grey-brown with scattered off-white spots and numerous black setae; venter of opisthosoma mottled grey-brown and off-white.

Chelicerae. Segment I 1.0, segment II 2.0. Orange, with dorsodistal part of segment I white; distal half of second segment lighter.

Pedipalp. Femur 1.4, patella 0.6, tibia 0.8, tarsus 2.0. Striped dark brown and tan; small pointed patellar apophysis with hypersetose region on medial edge.

Legs. Leg I femur 3.5, patella 1.0, tibia 3.0; leg II femur 6.5, patella 1.5, tibia 6.5; leg III femur 3.5, patella 1.0, tibia 3.0; leg IV femur 5.0, patella 1.0, tibia 4.5. Grey-brown, spotted with white. Tibia II with six or seven pseudosegments; tibia IV with two pseudosegments.

Comments. Forster (1944) refers to two specimens in his original description, but the type vial only includes a single specimen. To forestall confusion, this specimen is here designated as the lectotype. The status of the other specimen is currently unknown.

Forsteropsalis nigra is easily distinguished from F. chiltoni by its heavy denticulation, and there seems to be no reason to retain the former as a subspecies of the latter. Forster (1944) may have based his identification on misidentified specimens of F. inconstans (see that species above). Forsteropsalis nigra can be distinguished from F. inconstans by the absence of a red stripe along the boundary between the anterior and median propeltidial areas. Note, however, that in some specimens of F. inconstans , the red stripe may fade and is difficult to distinguish from the surrounding background (personal observation).

Figures

FIGURES 121–123. Forsteropsalis nigra (Forster 1944), male holotype. 121. Prosoma, dorsal view. 122. Left cheliceral fingers, dorsal view. 123. Right pedipalp, retrolateral view. Scale bar for fig. 121 = 1 mm; figs 122–123 = 0.5 mm.