358 
B.Y. Main 
Table 1 Missulena torbayensis sp. nov., leg dimensions, 
holotype male. Tibial index = 100 X width of 
patella/length of tibia +patella (Petrunkevitch 
1942). 
Leg formula (length of leg divided by length 
of carapace): 
1/2.7, 4/2.62, 2/2.25, 3/2.15 
F 
P 
Ti 
Mt 
T 
Total 
I 
3.3 
1.8 
2.3 
2.2 
1.2 
10.8 
II 
2.8 
1.4 
1.8 
1.8 
1.2 
9.0 
III 
2.6 
1.8 
1.2 
1.8 
1.2 
8.6 
IV 
3.2 
1.9 
2.0 
2.1 
1.3 
10.5 
Palp 
2.8 
1.6 
2.4 
- 
1.0 
7.8 
Width of patella I at knee = 0.4; tibial index = 19.51 
Width of patella IV at knee = 0.8; tibial index = 20.51 
Variation 
There is some variation in body size and all 
meristic characters such as leg spination, maxillary 
and labial spinules and teeth on groove of 
cheliceral fang. Variation of carapace length/ width 
and numbers of teeth on inner, median and outer 
rows of right/left cheliceral groove of specimens 
additional to holotype from Torbay/West Cape 
Howe: 3.4/4.1; 8, 3+lminute, 3/7+several minute, 
3;-3 (BYM 85/83); 3.5/4.4; _ (BYM 83/143); 3.5/ 
4.6; 8, 4, 3/9,3,3 (BYM 84/82); 3.8/4.8; 9, 3, 3/7, 3, 
4 (BYM 87/12). 
BIOLOGY 
Habitat 
All the Torbay and West Cape Howe sites from 
where the spiders were collected are damp, shaded 
situations, although the ground may be dry on the 
surface during summer. The Rutherwood Road 
reserve is a mixed jarrah/redgum woodland with 
shrubby, close undergrowth. The pitfall traps were 
sited along a permanently shaded drainage course 
which although lacking defined banks is wet in the 
winter with some surface water. The granite knob 
above Dingo Beach provides runoff into a scrubby 
paperbark swamp. The Lake William heath site is 
along a gentle slope down to a creek which runs 
vigorously in the winter and its broad, flat bed is 
wet enough to provide habitat mounds for pitcher 
plants (Cephalotus follicularis). The other West Cape 
Howe site is a small karri forest grove in a gully 
which drains into the southwest side of Lake 
William. It is likewise permanently damp and the 
heavily littered ground is deeply shaded with a 
thicket of acacias, reeds and other shrubs. 
Phenology 
All the Torbay/West Cape Howe specimens 
were collected during late autumn/winter from pit 
traps which were permanently open for at least 18 
months. Similarly the Manjimup specimen was 
collected in a pitfall trap during winter. Hence it is 
deduced that like most other species of Missulena 
the species mates during the autumn/winter. The 
Shannon River specimen, although collected in 
February was described as entangled in an 
amaurobiid web. As the specimen was dead and 
dry it may have been in the web for several months 
(M.S. Harvey, pers. comm.) 
The lack of red or blue colouring of males of this 
species is of interest in relation to the habitat, that 
is, dark "closed canopy" situations. It is presumed 
that males, like most other species, wander during 
the daytime. It is probable that the bright colours 
of open habitat species are a defence against 
vertebrate predators and I postulate that such 
colouration mimics offensive insects such as 
mutillid wasps, although no specific models have 
been identified. Coyle and Shear (1981) suggested 
that the diumally wandering males of Sphodros 
species, which are similarly brightly coloured may 
"have evolved a defensive mechanism of 
generalized wasp-ant mimicry in response to 
selection pressure from visual vertebrate 
predators". Possibly the species of Missulena with 
entirely black males such as that of the species 
described here, are confined to habitats with low, 
dense vegetation where disruptive or warning 
colours would have no significance. 
ACKNOWLEDGEMENTS 
I thank M.S. Harvey for making available 
Missulena specimens in the Western Australian 
Museum collection. I am grateful for a permit from 
the Department of Conservation and Land 
Management to collect spiders in parks and 
reserves. I thank Tom Stewart for preparing the 
scanning electron micrographs. Helpful comments 
from two referees were greatly appreciated. 
REFERENCES 
Coyle, F.A. and Shear, W.A. (1981). Observations on the 
natural history of Sphodros abboti and Sphodros mfipes 
(Araneae, Atypidae), with evidence for a contact sex 
pheromone, journal of Arachnology 9: 317-326. 
Faulder, R.J. (1995). Two new species of the Australian 
spider genus Missulena Walckenaer (Araneae: 
Actinopodidae). Australasian spiders and their 
relatives: Papers honouring Barbara York Main. Records 
of the Western Australian Museum, Supplement No. 52: 
73-78. 
Main, B.Y. (1956). Observations on the burrow and 
natural history of the trap-door spider Missulena 
(Ctenizidae). Western Australian Naturalist 5: 73-80. 
Main, B.Y. (1985). Mygalomorphae. In D.W. Walton 
(ed.). Zoological Catalogue, 3: 1-48. Australian 
Government Publishing Service, Canberra. 
Petrunkevitch, A. (1942). A study of amber spiders. 
