118 
GEOFFREY J. WITTEN AND A. JOHN COVENTRY 
Population 
N 
Mean 
Females 
(SD) 
Range 
N 
Mean 
Males 
(SD) 
Range 
Big Desert 
9 
130.8 
(13.9) 
113-163 
11 
126.5 
(30.2) 
83-175 
Sunset Country 
8 
157.5 
(28.6) 
126-202 
6 
157.8 
(19.4) 
131-181 
Others 
6 
184.3 
(31.5) 
132-217 
8 
229.0 
(16.0) 
208-247 
Table 1. Size of mature Pogona vitticeps. 
D55064, 61 mm SVL) has ovarian follicles less 
than 0.4 mm in diameter. Big Desert females 
more than 92 mm SVL have ovarian follicles 
more than 1 mm in diameter. One of these spe¬ 
cimens (NMV D54759) has follicles of 6.5 mm 
diameter and a SVL of 113 mm; this was the 
smallest female that was clearly mature. Some 
larger mature females had ovarian follicles of 
less than 2 mm diameter. 
Specimens of P. vitticeps from outside the Big 
Desert mature at a larger size but the difference 
is not great. A female recorded as coming from 
“Gawler Ranges, Victoria” (but probably from 
South Australia; NMV D648) has opaque con¬ 
voluted oviducts at 128 mm SVL, and a female 
from near Hattah in northern Victoria was 
gravid at 126 mm SVL (NMV D11754). Two 
specimens recorded as coming from Ouyen pro¬ 
vide data of dubious significance. One of them 
(NMV D1031) was clearly immature at 97 mm 
SVL, having ovarian follicles of less than 1 mm 
diameter. The other (NMV D970) is only 114 
mm SVL yet has opaque convoluted oviducts. 
Ouyen is north-east of the Big Desert but is the 
nearest major centre of population east of the 
desert. The specimens are unlikely to have been 
collected from the township itself, and either or 
both of them may have come from the Big 
Desert or from the Sunset Country. Data from 
these specimens were excluded from all 
analyses. 
Males from the Big Desert clearly mature at a 
smaller size than those from elsewhere. One spe¬ 
cimen (NMV D18220, 83 mm SVL) has testes 
approaching 7 mm in length, and another of sim¬ 
ilar size (NMV D53836, 85 mm SVL) also has 
larger testes than immature animals (5.6 mm). 
In comparison, two males of P. vitticeps from 
Purnong in South Australia were immature at 
SVLs of 88 (NMV D4547; larger testis of 3.15 
mm length) and 93 mm (NMV D3072; 4.0 mm). 
Another specimen from Broken Hill (NMV 
D52089) was not mature at a SVL of 132 mm, 
the larger of its testes being only 4.2 mm in 
length. In these immature specimens the testes 
are flattened, contrasting sharply with the 
swollen, more circular testes of mature 
animals. 
Specimens of P. barbata from Victoria are not 
markedly smaller than those from populations 
elsewhere. A male from near Boort was 219 mm 
SVL (NMV D57127). However, a specimen 
from the south-west of the state (NMV DI4699) 
was a mature male of 95 mm SVL (larger testis 
7.45 mm), considerably smaller than the 130 
mm stated for mature individuals of bothsexes 
by Badham (1976). 
Morphometries 
Data were analysed to quantify allometry in 
growth. Allometric growth for all populations of 
P. vitticeps is very similar (Table 2), The head of 
P. vitticeps is wider than that of P barbata, espe¬ 
cially in larger animals. Aclear trend is apparent 
in the allometric data for head width, popula¬ 
tions of larger animals having a higher allomet¬ 
ric coefficient. For measurements apart from 
head width the different P. vitticeps populations 
do not differ substantially. The head is appar¬ 
ently larger in the populations of smaller ani¬ 
mals, particularly in juveniles (Table 2). 
External morphology 
Scale counts and other characters are very simi¬ 
lar in specimens of P. vitticeps from the Big 
Desert and from elsewhere (Table 3). A nuchal 
scale ridge formed by a few mucronate scales 
with their keels aligned is commonly present in 
all populations, this ridge continuing well onto 
the trunk in some animals from the Big Desert 
population. Individuals from the Big Desert 
population also commonly possess a paravert¬ 
ebral nuchal scale ridge (about 7 5% of specimens 
examined), consisting of a row of mucronate 
scales parallel to the nuchal scale ridge but a few 
scales lateral to it. A similar scale row is reported 
in P. minimus (Badham 1976, fig. 4e). Other 
populations of P. vitticeps also commonly pos¬ 
sess the paravertebral scale row but the nuchal 
scale row seldom continues posteriorly. 
The venter of the Big Desert animals is com¬ 
monly patterned in the ocellations typical ot 
