DESCRIPTION OF PSEUDOMYS NOVAE-HOLLANDIAE 11 
all specimens suspected of immaturity being excluded. The 
ear measurement is taken from the notch at the base of the 
concha to the extreme tip. 
Skulls. — The variation in skulls of hermannshurgensis 
from the two localities is similar; it is not possible to find 
any character that will separate them, as all measurements 
overlap. 
Colour of pelage. — ^Whilst the general tone of the South 
Australian hermannshurgensis is, on the whole, slightly colder 
than in Central Australian examples, the intergrading is so 
complete and so widely overlapping that it is of no practical 
use as a distinguishing character. 
Comparison of hermannshurgensis with novae-hollandiae. 
The generic name Pseudomys (Gray, 1832) was revived by 
Oldfield Thomas (3) in 1910, when he separated the Australian 
mice from other forms. He divided the genus into four 
subgenera, Pseudomys s.s., Thetomys, Leggadina and Gyomys. 
He placed hermannshurgensis in Leggadina, of which he said : 
“Size small. Form of skull normal. Anterior zygomatic plate 
straight or convex in front as in ordinary murines. Palatal foramina 
narrow. Pterygoid region peculiar, the parapterygoid fossae broad 
and very shallow, scarcely hollowed at all, the ectopterygoids bordering 
it externally low, flat, not or scarcely raised up above the level of its 
floor; entopterygoids also much lower and less projecting than usual. 
Molars very variable, but always with a well-marked anterio-internal 
cingular cusp on Mb In P. delicatiiliis this is small, in hermanns- 
burgensis intermediate, and in foresti very large. In proportion to the 
development of this cusp the laminae are themselves tilted backwards 
internally whilst the outer cusps are reduced in size.” 
He also designated novae-hollandiae as the type of Gyomys 
of which he said : 
“Size small. Skull as in Leggadina. Molars quite normal ; no 
anterior cingular cusp on M^, and the molar laminae quite of the usual 
murine shape and position.” 
Skull. — Though the available skulls of novae-hollandiae 
have the basi-occipital and pterygoidal regions cut away, those 
measurements which can be taken are completely within the 
limits of variation in hermannshurgensis. The general con- 
formation, and the shape of the front edge of the zygomatic 
plate, also, is identical. This is in accordance with Thomas’s 
description quoted above. 
