Megalopsalis stewarti (Forster, 1949) Forster, 1949

Taylor, Christopher K., 2013, Further revision of the genus Megalopsalis (Opiliones, Neopilionidae), with the description of seven new species, ZooKeys 328, pp. 59-117 : 85-86

Megalopsalis stewarti (Forster, 1949) comb. n. Figs 16, 18a

Spinicrus stewarti Forster, 1949: 68-70, figs 11-16.

Material examined.

Paratypes. 1 female, Victoria, Mount Buffalo, 30-31 December 1947, ex bole of snow gum ( Eucalyptus pauciflora ) (NMV K-8910); 8 males, ditto (NMV K-8911-8919).

Other material examined. 1 male, Victoria, Lala Falls, near Warburton, 37°46'S, 145°42'E, 22 December 2002, M. S. Harvey, M. E. Blosfelds, under bark of Eucalyptus regnans (WAM T72315).

Description.

MALE. Description as in Forster (1949), except following.

Legs. Leg I with anterior longitudinal row of enlarged denticles from proximal end of femur to distal end of tibia (males with smaller chelicerae with reduced denticle row on femur only), scattered denticles on basitarsus I; smaller row on femora and patellae of other legs.

Penis (Fig. 16). Shaft and tendon elongate; all four bristle-groups well-developed. Distinct lateral protrusion of glans above left anterior bristle group. Glans short, broad, triangular in dorsal view, dorsoventrally flattened at distal end. Pores shallowly recessed.

Spiracle (Fig. 18a). Reticulate spines extending only partway across spiracle; terminations of spines palmate; small group of lace tubercles in lateral corner.

FEMALE. Description as in Forster (1949), except all legs with dorsal longitudinal row of small denticles along femora.

Comments.

Forster (1949) stated that the holotype and female paratype had been deposited in NMV, while the remaining male paratypes (of unspecified number) had been deposited in the Canterbury Museum, Christchurch, New Zealand (CMNZ). However, as indicated above, NMV holds eight male specimens of this species labelled as paratypes. Because these specimens share the same collection data as the female paratype, it seems likely that these correspond to the specimens that Forster (1949) intended to place in CMNZ.

Megalopsalis thryptica is very similar to Megalopsalis stewarti , from which it can be distinguished by having distitarsus IV basally swollen. Hickman (1957) initially distinguished Megalopsalis stewarti from Megalopsalis thryptica by the presence of denticles on tibia I in males of Megalopsalis thryptica , compared to their supposed absence in Megalopsalis stewarti as described by Forster (1949). However, specimens of Megalopsalis stewarti with longer chelicerae also have more extensive denticulation on leg I, extending as far as the basitarsus in some specimens. There is insufficient data as yet to determine whether this indicates a division between major and minor males or whether variation is continuous. Megalopsalis thryptica may still be distinguished from Megalopsalis stewarti by the male of the former having distitarsus IV basally inflated (personal examination of holotype, AMS).