240 Mr. O. Thomas on African Mole-Rats. 
shares with it the possession of a white crown-patch, short 
fur, and thickened outer wall to the anteorbital foramen, all 
of which characters separate it from G. cecutiens. From 
G. damarensis it may be distinguished by its conspicuously 
smaller size, less extended crown-patch, and much shorter 
nasal bones. 
The species having been first obtained by Mr. Darling, I 
have named it in his honour, although I have found it most 
convenient to take one of Mr. Marshall’s Salisbury specimens 
as the actual type. 
Mr. Darling states that the native name is “ Nota,” and 
both collectors say that it is very common on the open veldt. 
Since it is so common, I venture to hope that both col- 
lectors will send many more specimens, so that, at least in 
one species of this difficult group, we may learn something 
definite about the seasonal, age, and sexual variations—a 
knowledge that would be of the utmost value in working out 
other members of the group. 
Il. The Central-African Georychi. 
In 1887 * Prof. Leche, of Stockholm, in working out a 
collection received from Emin Pasha, mentioned and figured 
two large Georychi as G. damarensis, Og., and G. ochraceo- 
cinereus, Heugl. ‘The first of these determinations was made 
on my authority after a comparison with the type, as at that 
date I by no means realized the importance of the difference 
in colour and locality between the two. Later on T, influenced 
by the character of size and by the resemblance of the smaller 
animal to G. damarensis, I suggested that the names should 
be reversed, and that the smaller sandy-coloured animal 
should be called damarensis and the larger smoky-grey one 
ochraceo-cinereus. 
In now re-examining the subject, I have come to the con- 
clusion that Prof. Leche was in the first instance perfectly 
correct in referring the sandy-coloured species to Heuglin’s 
G. ochraceo-cinereus, and that this also is the most nearly 
allied to G. damarensis, while the darker species is equally 
distinct from both, and therefore needs a new name. 
As it was entirely due to my original error that this species 
was not described by Prof. Leche in the first instance, I 
venture now to name it, in honour of that distinguished 
inammalogist, 
* Zool. Jahrb. iii. p. 120 (1887). 
+ P. Z. S. 1888, p. 14. 
