Forsteropsalis inconstans ( 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 : 55-56

publication ID 10.11646/zootaxa.2773.1.1

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Forsteropsalis inconstans ( Forster 1944 )

new combination

Forsteropsalis inconstans ( Forster 1944) new combination

( Figs 111–114 View FIGURES 111–114 )

Megalopsalis inconstans Forster 1944: 187–188 , figs 4–6.

Megalopsalis chiltoni (Hogg) — Forster 1944: 185–186, pl. 65, figs 7–9 (in part; misidentification).

Megalopsalis fabulosa (Phillipps & Grimmett) — Forster 1944: 186–187, figs 10–11.

Material examined. Female holotype. WN. Akatarawa, New Zealand, 1 January 1943, R . Forster ( MONZ 2 View Materials /22) .

Other material examined ( MONZ): WN. 2 females, Akatarawa , 1 January 1943 ; 1 male, Akatarawa , 21 January 1945 ; 1 female, Johnson’s Hill , Karori, New Zealand, 21 December 1946 , under logs; 3 males, Karori , 16 November 1941 ; 1 male, Karori , 26 February 1942 , beaten from “niggerhead” [probably Carex secta ]; 1 male, Karori Hills , 1 February 1942 , R. Forster ( MONZ 2 View Materials /24, neotype of Macropsalis fabulosa ); 2 males, Karori Hills , 1 February 1942 , under log [identified as M. fabulosa on label]; 1 male, Silverstream , New Zealand, 15 February 1920 ; 1 juvenile male, Silverstream , 18 July 1920 .

Description. MALE (N = 6). Prosoma length 1.8–2.4, width 3.0–3.2. Prosoma dark brown with orange or red U-shaped stripe around ocularium; heavily denticulate. Ocularium dark brown; denticulate. Dorsum of opisthosoma dark brown with grey lateral punctures, white spots on lateral margins. Coxae dark brown with white patches; venter of opisthosoma light brown.

Chelicerae. Segment I 4.5–7.5, segment II 6.5–10.0. Dark brown, except for dorsodistal orange patch on segment I; both segments denticulate. Cheliceral fingers bowed slightly apart proximally; mobile finger angular crescent-shaped (fig. 112).

Pedipalps. Femur 1.6–1.9, patella 0.8–1.0, tibia 1.0–1.4, tarsus 2.2–2.8. White with reddish base; femur with ventral longitudinal row of denticles; very small, pointed apophysis on patella. Microtrichia on entire tarsus and distalmost end of tibia; no tooth-row on claw.

Legs. Leg I femur 4.5–6.8, patella 1.0–1.3, tibia 3.5–5.0; leg II femur 6.5–10.5, patella 1.0–1.8, tibia 6.5–9.5; leg III femur 3.5–5.8, patella 1.0–1.5, tibia 3.5–4.8; leg IV femur 5.5–7.5, patella 1.3–1.5, tibia 4.0–6.0. Dark brown with orange spots, except metatarsi and tarsi silver-brown; trochanters unarmed; femora denticulate. Tibia II with six or seven pseudosegments; tibia IV with two pseudosegments.

Penis (figs 113–114). Bristle groups relatively short. Glans bent dorsad relative to shaft; long, slender, sides parallel in ventral view; no dorsolateral keel. Pores on small emarginate papillae.

Spiracle. Dense curtain of reticulate spines over spiracle; terminations of spines not successfully observed.

FEMALE (N = 4). Prosoma length 2.0–2.6, width 2.8–3.2. Prosoma mottled medium brown and white; two white longitudinal stripes from either side of ocularium to anterior margin of prosoma; few scattered black setae. Ocularium medium brown with thin black margins around eyes; few black setae. Dorsum of opisthosoma with medium brown square ‘saddle’; rest of dorsum mottled tan and medium brown except for light grey medial stripe behind saddle to posterior end of opisthosoma. Coxae grey-brown reticulated with white; venter of opisthosoma grey-brown spotted with white, few black setae.

Chelicerae. Segment I 1.0–1.5, segment II 2.5–3.0. Medium brown mottled with white; black setae.

Pedipalps. Femur 1.4–1.8, patella 0.6–0.8, tibia 0.9–1.0, tarsus 2.2–2.4. Femur dark brown striped with white, unarmed; patella and tibia medium brown proximally, tan distally; tarsus tan; patella with small, pointed apophysis; black setae in longitudinal rows on patella and tibia; apophysis hypersetose.

Legs. Leg I femur 3.3–4.8, patella 1.0, tibia 3.0–4.3; leg II femur 8.5–8.8, patella 1.5–1.8, tibia 7.8–8.3; leg III femur 3.0–4.8, patella 1.0, tibia 3.0–4.3; leg IV femur 6.5–7.0, patella 1.5, tibia 5.8–6.0. Striped medium brown and tan with white spots; femora denticulate. Tibia II with six or seven pseudosegments, tibia IV with two pseudosegments.

Comments. Forster (1944) misidentified specimens of Forsteropsalis inconstans as belonging to three separate species: females were identified as Megalopsalis inconstans whereas males were divided between M. chiltoni and M. fabulosa (see under the latter for the misidentification of F. inconstans as that species). Males of F. inconstans differ in the degree of dilation of the second cheliceral segment (compare figs 9 and 10 of Forster 1944), and Forster used ‘M. chiltoni’ for males with narrower chelicerae than ‘M. fabulosa’. The cheliceral variation shown by F. inconstans appears to be continuous rather than representing discrete polymorphisms.

Forsteropsalis inconstans can be distinguished from other species of Forsteropsalis , except F. nigra , by the heavy ornamentation on the dorsal prosomal plate; even in a group known for extravagant ornamentation, the high, almost Gothic degree of denticulation exhibited by the males of F. inconstans and F. nigra stands out. Forsteropsalis inconstans can be distinguished from F. nigra by the red markings on the propeltidium.


Departamento de Geologia, Universidad de Chile


Museum of New Zealand Te Papa Tongarewa - Entomology














Forsteropsalis inconstans ( Forster 1944 )

Taylor, Christopher K. 2011

Megalopsalis inconstans

Forster, R. R. 1944: 188

Megalopsalis chiltoni (Hogg)

Forster, R. R. 1944: 185

Megalopsalis fabulosa (Phillipps & Grimmett)

Forster, R. R. 1944: 186