EURYOTIS UNISULCATUS. 
edge of the tooth ; those of lower jaw plain. For further details, see letter- 
press to PI. XXV. 
DIMENSIONS. 
Inches. Lines. 
Length from the point of the nose to 
the tip of the tail 10 6 
of the tail 3 6 
Distance between the nose and the eye 0 9 
between the eye and the ear 0 9 
Inches. Lines. 
Length of the fore-legs 1 1 
liind-legs 2 1 
tarsi of hind-legs 1 0J 
Height when standing 2 6 
The surface colours of the female are rather darker than those of the male. 
This species does not occur so far to the southward and westward as E. irroratus ; its favo- 
rite resort appears to be arid localities in the central and eastern districts of the colony. Be- 
sides aridity and a certain quantity of soft sandy soil, the existence of a shrubby vegetation 
appears also essential, at least it is only found in situations so provided. Its existence or non- 
existence in a locality is readily ascertained ; if it exists, large hemispherical or irregular 
masses, composed of an aggregation of small dry twigs, will be seen, more or less, surround- 
ing the’ stems, of such shrubs as occur, and even often advancing high among their branches. 
These masses are formed by the animal, and are traversed in all directions by its burrows. 
Under such piles, and in the passages by which they are intersected, the animal seeks shelter 
and safety from danger, at the same time, like E. irroratus, it is moreover provided with 
deeper-seated retreats, into which it may retire should its comfort or safety appear to render the 
step necessary. The last-mentioned retreats consist of subterranean burrows, not extending 
beyond the area covered by the accumulated twigs, but much branched ; and in all cases in 
which we have followed up individuals and secured them, we invariably required first to demo- 
lish the superincumbent mass, and then explore the underground burrows. In the latter, the 
female generally, though not invariably, produces her young, and these, when discovered, are 
enclosed in a nest consisting of soft dry grass. 
The general colour of E. unisulcatus is considerably lighter than that of E. irroratus, but 
decidedly darker than that of E. Brantsii. The incisors of the lower jaw, being without 
grooves, furnish one of the most available diagnostic characters ; the great size of its ears, 
when compared with those of the other two species, also affords means by which it is to be 
readily distinguished from them. 
