524 On the Arctonyx of Annam. 
“‘ Under trees ; holes made in naked soil.” —Z. B. 
This is a paler form of the more northern C. coludo of 
Tinogasta, Catamarca, with which it agrees in_ essential 
characters. The intermediate C. famosus of the Famatina 
chain should also, I think, be considered as only sub- 
specifically separable from coludo. 
The southern neighbour of this tuco-tuco is C. mendocinus, 
Phil., which differs widely from it by its less narrow skull, 
its smaller bulle, and larger cheek-teeth. 
LXII.—The Arctonyx of Annam. 
By OLDFIELD THOMAS. 
(Published by permission of the Trustees of the British Museum.) 
AmonG the collections contributed by Dr. Vassal to the 
National Collection there is an example of a hog-badger 
which, on comparison with those in the Museum, would seem 
to represent a distinct form. 
Arctonyx anneus, sp. n. 
Size apparently approaching that of A. dictator, judging 
by the typical skull, which, although immature, already 
exceeds in length thosé of the other smaller species. Quality 
of fur and coloration about as in A. collaris, the markings 
net so strongly contrasted as in dictator, their distribution 
quite as usual, 
Skull, of an immature specimen, already longer than in 
adult specimens of A. collaris and obscurus, and approaching 
in length that of the large A. dictator of Tenasserim and 
S. Siam, which it probably equals when fully adult. 
Upper molar comparatively long and narrew, with a 
marked concavity at the middle of its inner edge, its length 
decidedly greater than in the smaller species, its breadth less 
than in the larger. And the same with the large lower molar. 
Dimensions of the type-skull :— 
Condyle-basal length 142 mm.; zygomatic breadth 68 ; 
length of nasals 42; palatal length to back of pterygoids 107; 
p*, length on outer edge 9°8, greatest breadth 9°2 ; m’, greatest 
length ‘(diagonally) 17: 5, breadth at central internal notch 9°6; 
Hab. Avnam. Type from Nha-trang. 
Type. Immature male. B.M. no. 10. 3.10.4. Collected 
29th March, 1909, by Dr. J. Vassal. 
This species has the external appearance of A. collaris, 
but is nearly or quite as large as A. dictator, from which it 
differs by its narrow upper molar. 
