Iridonyssus, Raven, 2015

Iridonyssus View in CoL gen. nov.

Diagnosis. Resembles Nyssus but differs in that the eyes are the most anterior point of the carapace and on the vertical face of the clypeus ( Fig. 1d View FIGURE 1 ), not set back as in other genera, flatter cephalothorax and closed post-epigastric sclerites ( Fig. 40c View FIGURE 40 ) and steep posterior slope of carapace ( Fig. 1d View FIGURE 1 ). Iridonyssus is readily differed from other Australian corinnids by the pustulose iridescent carapace ( Figs 39 View FIGURE 39 , 40a View FIGURE 40 , 42a View FIGURE 42 ) and from Poecilipta in the relatively wider carapace and much shorter legs.

Etymology: a combination of iridescent and Nyssus . The gender is masculine.

Type species: Iridonyssus kohouti View in CoL sp. nov.

Description. Carapace and abdomen heavily sclerotised, pustulose and iridescent but for large white feathery scales laterally. Carapace steep-sided behind and in eye region. Lateral profile of carapace ( Fig. 1d View FIGURE 1 ): low and flat or slightly arched for its length but sloping downward to eyes from steep posterior declivity; eyes set behind clypeus edge. Retrolateral face of small chelicerae smooth ( Fig. 40b View FIGURE 40 ). Abdomen (female, Fig. 40a View FIGURE 40 ) with heavy dorsal scute extending down lateral face and close to but separated from genital and ventral scutes. Eyes in two rows ( Fig. 40b View FIGURE 40 ); all of similar size; front row recurved, back row procurved ( Fig. 44d View FIGURE 44 ). Spines: tibia I v2.2; me v2.2, all weak. Tracheal spiracle a transverse slit with low anterior mound, in males often fused to ventral scute ( Fig. 42b View FIGURE 42 ) or long ovoid in females ( Fig. 40d View FIGURE 40 ). RCH a pinhole. Palp: cymbium lacks paracymbial spine ( Fig. 41a View FIGURE 41 ); bulb typical of Castianeirinae , with twisted embolic apex. Scopula absent; claw tufts well developed. Chelicerae small with short fangs, with line of long serrate setae on fang mound ( Figs 4d, e View FIGURE 4 , 40b View FIGURE 40 ) of females. Large thick setae in front of fang. Male chelicerae without modified setae. Sternum pustulose ( Fig. 42c View FIGURE 42 ). Femora III and IV with strong ventral distal constriction ( Fig. 42d View FIGURE 42 ). Female with ventral scute reduced to tracheal shield ( Fig. 40d View FIGURE 40 ); genital shield forms a short collar ( Fig. 40c View FIGURE 40 ); full dorsal shield coloured and pitted; paragenital brackets present ( Fig. 40d View FIGURE 40 ). Epigyne ( Fig. 40c View FIGURE 40 ) heavily sclerotised; two basal ovoid pits leading forward to large receptacle and then back.

Species included: Iridonyssus auripilosus sp. nov., I. formicans sp. nov., I. kohouti sp. nov. and I. leucostaurus sp. nov.

Distribution. Eastern Australia.

Key to species of Iridonyssus View in CoL

1. Carapace and abdomen with iridescent peacock green sheen ( Figs 39 View FIGURE 39 , 40a View FIGURE 40 )................................. I. kohouti View in CoL

Carapace and abdomen not as above....................................................................... 2 2(1). Broad golden scales covering carapace lightly and dorsal scute densely ( Fig. 42a View FIGURE 42 )… I. auripilosus View in CoL

No such scales........................................................................................ 3 3(2). Radial lines of pallid hair on interstrial ridges of carapace ( Fig. 47a View FIGURE 47 ).................................. I. leucostaurus View in CoL

Carapace without hair ( Fig. 44a, b, d View FIGURE 44 )............................................................. I. formicans View in CoL

MAPS 19–24. Records of Australian species of Disnyssus View in CoL gen. nov., Iridonyssus View in CoL gen. nov. and Kolora View in CoL gen. nov.