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Show 1906.] MAMMALS FROM WESTERN AUSTRALIA. 775 45. L agorchestes hirsutus bernieri, subsp. n. Ten males; seven females. General characters as in the typical subspecies ; but the fur is not nearly so long (hairs of back in winter specimens about 18 mm., wool-hairs 12 mm., instead of 32 and 24 mm. respectively) ; the ears are slightly shorter; the long hairs on the feet are of a more glossy sandy colour, instead of brownish ; and the tail, instead of being well-haired throughout and blackish on the upper side of the terminal half, is practically naked above, the few minute scattered hairs being sandy. The skulls are remarkably uniform in character ; but, no equally good material existing of the true L. hirsutus, it can now be stated oidy that the bulla?, in correlation with the shorter external ear, are very decidedly smaller than in the type. The interorbital is broad and parallel-sided. Dimensions of the type, measured in the flesh :- Head and body 370 mm.; tail 270; hind foot s.u. 112, c.u. 125 ; ear 48. Skull-greatest length 76 mm. ; basal length 66 ; greatest breadth 41*5 ; nasals 30 x 11*8; interorbital breadth 12*9; palatal length 42; length of secator 4*7; combined length of three anterior molar if onn teeth 15#2. IIah. Bernier Island, Shark's Bay. Type. Adult male. B.M. No. 6.10.5.18. Original number 571. Collected 16 June, 1906, by G. C. Shortridge and presented by Mr. W. E. Balston. This animal, which differs from its mainland relations in very much the same way as do the other two Rat Kangaroos of the island from theirs, is fortunately able to take its proper position in nomenclature as an insular subspecies of L. hirsutus, the mainland form having in this case been first described. No record exists as to how far north the true L. hirsutus occurs, the only specimen with an exact locality that I am aware of being the type, which was obtained by Mr. Gilbert at York, in the Avon district inland of Perth. But further, a careful comparison of two specimens obtained by Mr. J. T. Tunney on Dorre Island, just to the south, with the series from Bernier Island shows that a slight difference has already been developed between the two; and one that I think should be recognised by name. The Dorre Island form may therefore be called Lagorchestes hirsutus dorrece. Externally the differences are not essential, though it may be noted that the fur of clorrece is slightly softer, and in one example longer (specimens obtained in the southern summer, and compared with winter specimens of bernieri), though not so long as in true hirsutus, and that the ground-colour is more rufous, the ordinary and wool hairs, and not only the long piles of the rump, having a tinge of sandy rufous. The skull may be at once distinguished from that of bernieri P roc. Z ool. Soc.-1906, No. LII. 52 |