71 
A NECESSARY AMENDMENT TO THE DESCRIPTION OF TAUTATUS. 
By C. Boprn Kuogs, F.z.s. 
The advent of a second and older specimen of Tautatus thai 
(antea, p. 63) renders it necessary to amend the definition of the 
genus* which should be as follows :— 
GENUS Tautatus, descr. emend. 
Skull with superficial resemblance to Mus but the rostrum shallower and 
no masseteric knobs at the anterior bases of the zygomatic plates. No raised 
supraorbital ridges, the edges even more round than in Mus. Palatal foramina 
long, extending posteriorly well between the first molars ; palate extending well 
beyond the posterior extremities of the last molars. Mesopterygoid space 
normal, slightly diverging posteriorly. Bulle of medium size. 
Incisors notched and upper molars with proportions as in Afus, ml being 
longer than m2 and m3 combined ; but laminw of ml less distorted, the inner 
tubercles less posteriorly situated. ‘The remaining molars of more angular out- 
line : the anterior edge of m2 straighter owing to the more advanced position 
of the antero-internal tubercle ; the internal edge short and followed by an 
oblique postero-internal edge almost concave: antero-internal point of m3 form- 
ing the apex of a markedly triangular tooth. 
External characters apparently not peculiar : fur dense, rather long and 
stiff but not mixed with flattened spines. Hind-foot with fifth toe reaching 
to the middle of the basal phalanx of the fourth. Only the pollex with a flat 
nail. Ears of medium size. 
The principal differences from Mus, therefore, lie in the absence 
of the masseteric knobs and the less distorted form of the molars. 
In the specimens examined the premaxillaries do not extend beyond 
the posterior terminations of the nasals and this may possibly consti- 
tute another character. 
* Journ. N. H. 8. Siam, IT, p. 279 (1917). 
VOL. III, NO. I, 1918, 
