In previous communications on the rhinoceroses (Rhinoceros Contributions 1 to 11), Osborn separated six distinct phyla or subfamilies. The remarkable discoveries by Clive Forster Cooper in Baluchistan, by A. Borissiak in north Turkestan, and by Walter Granger of the Third Asiatic Expedition in southeastern and central Mongolia, indicate the existence of a seventh subfamily which we may term Baluchitheriinw, if the generic name proves valid. At present our knowledge rests on the following materials:

BUGTI HILLS, Chur-lando, Baluchistan. Cooper Collection, British Museum. Paraceratherium bugtiense Cooper, December 1911. Fairly complete skulls and lower jaws of about the size of a large rhinoceros, simple aceratherine molars, abnormal lower incisors. Y'haumastotherium osborni Cooper, October 1913, changed to Baluchitherium osborni Cooper, November 1913. Fragmentary skeletal remains found in close proximity to Paraceratherium, including neck vertebrae, foot and limb bones of elephantine size. TURGAI, a province of north Turkestan. Discoveries by A. Borissiak, published 1915-1918. Indricotherium asiaticum Borissiak, 1916. Teeth, skull, and skeletal remains, occurring in situ and resembling both Paraceratherium and Baluchitherium. Epiaceratherium turgaicum Borissiak, 1918.2 LOH, central Mongolia, Third Asiatic Expedition Collection, 1922. Associated skull and skeletal remains similar in size to the type of Baluchitherium osborni. Baluchitherium grangeri, new species. Type, nearly complete skull and jaws (Amer. Mus. 18650) associated with parts of vertebrae and of limb bones, as described in the present bulletin. IREN DABASU, southeastern Mongolia. Baluchitherium ref., calcaneum and other fragments of skeleton.