Australian Arrenurus 
255 
Arrenurus (Dividuracarus) subgen. nov. 
Type species 
Arrenurus (Dividuracarus) tripartitus sp. nov. 
Diagnosis 
Male 
Characters of Arrenuridae. Body divided in three 
parts with complete suture lines, middle part 
analogous with dorsal shield. Posterior part with a 
large median cleft. D1 and D2 on anterior body 
part, close to each other, D3 and D4 on posterior 
body part. No petiole present, but instead a 
protrusible, hyaline tube-like structure. 
Female 
Without subgeneric characters. Genital plates 
reversed bowed. 
Remarks 
The very unusual division of the body together 
with the tube-like structure is not found in any of 
the Arrenuridae. 
Arrenurus (Dividuracarus) tripartitus sp. nov. 
Figures 65-69 
Arrenurus spec. B Smit, 1992:110. 
Material Examined 
Holotype 
8, Jones River, east of Roeburne, Western 
Australia, Australia, 17 August 1994 (WAM). 
Paratypes 
Australia: Queensland: 1 2, Cloncurry River, 
Cloncurry, Queensland, 14 August 1989 (ZMA). 
Western Australia: 1 2 , Fortescue Falls (pool), 
Hamersley Range National Park, 11 August 1994 
(ZMA); 1 2, Pond Kalamina Gorge, near falls, 
Hamersley Range National Park, 13 August 1994 
(WAM); 1 8,2 2,1 nymph. Palm Pool, Millstream- 
Chichester National Park, 15 August 1994 (ZMA); 
1 8,4 2 , Small pond near Crossing Pool, 
Millstream-Chichester National Park, 16 August 
1994 (WAM); 1 8,2 2 , Pond Snake Creek, 
Millstream-Chichester National Park, 17 August 
1994 (NTM); 1 2 , Ashburton River at crossing with 
North West Coastal Highway, 18 August 1994 
(ZMA). 
Diagnosis 
As for subgenus. Body colour orange to yellow. 
Ventral body part of male extending well beyond 
dorsal body part. Female with distinct 
posterolateral comers of the body. 
Description 
Male 
Body 922 (912-931) long (without tube-like 
structure) and 621 (592-640) wide. Body colour 
orange to yellow. Body divided in three parts, with 
complete suture lines (Figure 67). Posterior body 
part with a large median cleft. Suture lines between 
CXI and CX2 and between CX3 and CX4 
incomplete. Gonopore 48 long. Genital plates 
bowed, not extending to lateral body margin 
(Figure 65). No normal petiole present, but a 
complicated, hyaline tube-like structure with the 
anterior part rounded and sclerotized; hyaline tube 
protrusible, open posteriorly and laterally, with 
serrated lateral margins (Figure 66). D2 shifted to 
anterior body part, D3 and D4 on middle part, D3 
shifted laterally. Lengths of PI-PV: 31, 79, 48, 84, 
38; PII with 2 setae on medial side (Figure 68). 
Lengths of I-leg-4-6: 116, 116, 97; lengths of IV-leg- 
4-6: 175, 155, 163. IV-leg-4 without a spur; second, 
third and fourth legs with numerous swimming 
setae. 
Female 
The female has been referred to by Smit (1992) as 
Arrenurus spec B. Body 892 (854-946) long and 752 
(698-800) wide. Body with distinct posterolateral 
corners. Dorsal furrow incomplete, dorsum 
without humps. Medial margin of CX4 larger than 
medial margin of CX3. Medial distance of CX4 less 
than width of one genital valve. Gonopore 155 
long; genital valves without chitinous patches. 
Genital plates short, reversed bowed (Figure 69). 
Posterior body part truncated. Lengths of PI-PV: 
34, 86, 58, 82, 46; PII with three setae on medial 
side. Lengths of I-leg-4-6: 116, 116, 92. Lengths of 
IV-leg-4-6: 184, 194, 155. Second, third and fourth 
legs with numerous swimming setae 
Remarks 
For discussion see A. gereckei sp. nov. 
Etymology 
The species is named for the division of the body 
in three parts. 
Arrenurus (Dividuracarus) gereckei sp. nov. 
Figures 70-73 
Material Examined 
Flolotype 
8, Lake Jabiru, Jabiru, Northern Territory, 
Australia, 20 July 1994 (NTM). 
Paratype 
Australia: Northern Territory: 1 8 (not fully 
sclerotized), same data as holotype (ZMA). 
