Body dimensions in Simoselaps and Vemticella 
71 
Table 2 The mean tail-body ratios (TBR) for males and females of Simoselaps and Vermicella together with standard 
deviation, range and sample size. 
Species 
Sex 
No 
Mean TBR 
SD X 10•’ 
Range 
Mid-Point 
M 
18 
.1461 
7.32 
.1317-.1612 
.1241 
S. anomalus 
F 
5 
.1048 
6.87 
.0994-.1164 
M 
14 
.1039 
6.16 
.0945-.1133 
.0945 
S. approximans 
F 
10 
.0814 
8.16 
.0676 - .0945 
M 
86 
.1341 
9.48 
.1127-.1525 
.1122 
S. bertholdi 
F 
80 
.0923 
7.96 
.0777 - .1116 
M 
27 
.1031 
7.04 
.0915-.1157 
.0858 
S. bimaculatus 
F 
28 
.0707 
5.06 
.0589 - .0800 
M 
36 
.1642 
9.28 
.1428-.1818 
.1397 
S. calonotos 
F 
32 
.1269 
7.48 
.1116-.1366 
M 
29 
.1420 
8.50 
.1277-.1586 
.1222 
S. littoralis 
F 
40 
.1028 
8.38 
.0865-.1166 
M 
2 
.1359 
6.63 
.1312-.1406 
S. minimus 
F 
1 
.1024 
M 
9 
.0994 
6.06 
.0861 - .1044 
.0814 
S. roperi 
F 
2 
.0647 
12.1 
.0562 - .0766 
M 
64 
.1141 
8.19 
.0971 - .1347 
.0929 
S. semifasciatus 
F 
63 
.0772 
6.24 
.0648 - .0888 
M 
2 
.1328 
5.99 
.1285-.1370 
S. fasciolatus fasciatus 
F 
M 
18 
.1284 
5.79 
.1186-.1400 
.1052 
S. fasciolatus fasciolatus 
F 
17 
.0852 
12.5 
.0611-.0918 (.1233) 
M 
2 
.0710 
4.96 
.0675 - .0745 
.0615 
V. multifasciata multifasciata 
F 
6 
.0454 
7.98 
.0350 - .0555 
M 
4 
.0528 
2.08 
.0514 - .0558 
.0492 
V. multifasciata snelli 
F 
8 
.0403 
4.30 
.0328 - .0469 
exception that is probably due to the small sample 
size of females which contains a relatively high 
proportion of non-adult individuals. Conversely, 
the mean TVL was found to be larger in males than 
females in all species studied, which agrees with 
the findings of King (1989). 
In a number of species the difference between 
males and females is highly significant for both 
SVL and TVL (Table 1). This occurs particularly in 
those species where tire data set is relatively large. 
However, measurements of SVL and TVL do not 
allow determination of sex in themselves, rather, 
the two measurements taken as a ratio provide a 
useful tool for determining sex in these snakes. 
The results of the study indicate that each species 
of Simoselaps and Vermicella in Western Australia 
has a tail-body ratio that does not overlap between 
sexes (Table 1) and adds further support to Storr's 
(1967) finding. One large female S. fasciolatus 
fasciolatus, with an exceptionally long tail, is 
responsible for the sole instance where overlap 
occurs in the male and female tail-body ratio 
ranges (Table 2). 
The degree of confidence in determining the sex 
of specimens is greatly reduced where the data set 
is small, e.g., S. minimus, and tail-body ratios that 
fall within this zone of separation may prove 
difficult to assign to sex. Consequently, in Table 2 
the mid point of the zone of separation for each 
species is presented as a value above and below 
which the sex for each individual can be assigned. 
Significant variation in tail-body ratios is present 
between the same sexes of the two subspecies of 
Vermicella multifasciata. However, in the study there 
were insufficient specimens of S. fasciolatus fasciatus 
to make a useful comparison of the TBRs with the 
subspecies S. fasciolatus fasciolatus. 
Storr (1967) found the absolute size of S. bertholdi 
specimens increases from the southwest to the 
north and east and that tire relative length of their 
tails similarly increases. No overlap is found in the 
male and female TBRs of S. bertholdi from three 
different geographical regions even though the 
mean TBRs for male specimens from the southwest 
are significantly lower than the other two regions. 
CONCLUSION 
The greater Perth Metropolitan region of Western 
Australia has a rich and abundant reptile fauna 
comprising over 70 species. Since European 
settlement this fauna has been modified by 
development in the form of agriculture and 
urbanisation with the result that most species now 
