562 SCIENCE PROGRESS 



has undergone divergent development. No fewer than four 

 new generic terms are proposed for the early Tertiary repre- 

 sentatives of the latter, the first two of these being based, 

 respectively, on Cuvier's Rhinoceros minutus and Filhol's 

 Aceratherium minus, while the other two are established on 

 new species, one from the lignite beds of Monte Bolca and the 

 other from the Oligocene of Krain. Special classificatory 

 importance is accorded to the form of the last upper premolar 

 tooth, of which the oldest type is found in Hyrachyus, where 

 the two cross-crests converge on the inner side to form a 

 U-like loop. From this may be traced a gradual transition to 

 the modern rhinoceros-type, in which the last premolar has 

 become like the molars, the first two of which carry a pair of 

 completely sundered and parallel cross-crests. Progressive 

 increase in the complexity of the upper molars themselves is 

 likewise noticeable as we pass from the earlier to the later 

 Tertiary species. 



Dr. Anton Koch has likewise described {Ann. Mus. Nat. 

 Hungar. vol. ix. pp. 371-87) certain well-preserved remains 

 of a small and primitive rhinoceros from the Middle Oligocene 

 of the Kolozsvar district. It is referred to the above-named 

 species, which is now known as Prceaceratherium minus. 



In 1910 Mr. F. Roman described {Ann. Soc. Linn. Lyon, 

 vol. lvi. pp. 117-30) a skull of the Miocene Rhinoceros 

 sansaniensis in the Museum at Nerac, and likewise contributed 

 a preliminary note (C. R. Acad. Sci. Paris, vol. cl. pp. 1558-60) 

 on the Oligocene rhinoceroses of Europe generally. The 

 latter subject he has further elaborated during the present year 

 in a memoir published in vol. xi. pp. 1-92 of the Archives of 

 the Lyons Museum. Two skulls, respectively belonging to 

 R. antiquitatis and R. mercki, from the Pleistocene of Thuringia 

 are described and figured by Mr. O. Wust in the Stuttgart 

 Palceontographica, vol. lxviii. pp. 133-88, pi. x. 



In America remains of rhinoceroses with a transverse pair 

 of nasal horns {Diceratherium) are found in splendid preservation 

 in the Agate Spring Quarries of Sioux County, Nebraska, 

 among them being a complete skeleton which has been mounted 

 in the Carnegie Museum, Pittsburg. In describing this specimen 

 Mr. O. A. Peterson {Ann. Carnegie Mus. vol. vii. pp. 274-7) 

 remarks that it " represents an animal with a well-proportioned 

 head, a short neck, a long and rather heavy body supported by 



