90 
Annals of the Transvaal Museum. 
Peters’ $ specimen would seem to have been a very young one, judging 
by the measurements recorded and the figure of the skull. The following 
measurements may therefore be of interest : — 
Old (J. 
Ad. <$. Young ad. <f. 
H. and B. ... 
... 161 
— 130 
Tail 
... 137 
— 120 
Hd. ft. 
... 30 
— 31 
Ear 
Skull : — 
... 20 
— 17 
Gr. leng. ... 
... 36*5 
34-6 33*1 
Bas. leng. ... 
... 30 
29*4 27 
Zyg. br. ... 
... 17-6 
17*3 16-8 
Mol. ser. ... 
... 6-7 
6*9 6-3 
Nasals 
... 13x4 
13 x 3-7 12-5 x 
Br. M 1 ... 
... 2*1 
2*3 2-2 
185. Pelomys australis , spec. nov. 
Similar to P. fallax , but with the tail longer than the head and body. 
(See P. S. 1907, p. 779). 
Type : Ad. <J, ex coll. C. H. B. Grant, Mazambeti, Beira (B. M. No. 7. 
6.2.51), now in the collection of the Transvaal Museum. “H. and B. 153, 
tail 165, hind foot 30, ear 18” (C. H. B. G.). Skull : gr. leng. 35 *3, bas. 
leng. 28*5, zyg. br. 16*8, mol. ser. 6*5, nasals 14 x 4, bullae 6. 
There are also two old specimens from N. W. Rhodesia (Wilde), which 
are somewhat larger than the type, but with the same proportionate length 
of tail. There are also five younger specimens from the same place which 
are given as having tails of about the same length as the head and body 
and a sixth with a tail much shorter than the head and body ; but, as it 
seems to be the rule that the growth of the tail is checked at a certain age 
in a number of different species of rodents, while the head and body still 
continue to grow even to very old age, I think it not unlikely that these 
six specimens are referable to a different species. This is supported in 
this case by the fact that the single large one in the series of six is 
obviously older than the other five, though of the same age as one of the 
two with very long tails. Should these specimens from N. W. Rhodesia 
therefore prove to belong to two species, we have the interesting over- 
lapping of the north and south of Zambezi species in the higher reaches 
of that river. This I have no doubt is the case, judging by comparison of 
specimens of the same age. The six specimens are not, however, referable 
to P. fallax , but more likely a western race linking up with the species 
found occurring in Angola. In these specimens measurements of the 
hind foot are given as 
size of the other parts. 
varying from 31 to 37 mm. 
without regard to the 
The following table of measurements will illustrate the facts above 
mentioned : — 
Old <$ and $. Old <$• Younger ($$ and 
H. and B. 
... 163 -164 
165 
135 -155 
Tail 
... 170 -177 
156 
133 -156 
Hd. ft 
... 32 - 36 
35 
31 - 37 
Ear 
Skull 
... 19 - 20 
20 
18 - 20 
Gr. leng. 
... 37-4- 37*5 
37*5 
33*1- 34 
Bas. leng. 
... 31 - 31*5 
30*8 
27 - 27*6 
Zyg.br. 
... 18*4- 19 
18*3 
16*6- 18 
