NOTES ON A NEW FOSSIL MAMMAL. 3 



lower, arc diameters which distinguish our fossil from all the forms 

 of hithei-to known Ungulates. As an evidence that it is not a 

 Sirenia, we may mention the differing ])osition of the nasal foramen, 

 the smooth surface of the upi>er jaw, the straight and not downwardly 

 curved anterior ends of hoth jaws, the larger number of incisors and 

 the peculiar form of the premolars and molars. 



The discovery of this fossil is very important to the palaeontology 

 of Japan. Ihit the hick of a sufficient literature concerning such fossils 

 in OUI- countrv com])elled us to submit it to the examination of some 

 recoofnized authority on vertebrate fossils abroad. So a brief 

 description of the skull and teeth, accompanied by photograplis, 

 were sent to Professor Osborx who was kind enough to inform 

 us, that the skull belonged to the Proboscidea. According to 

 this eminent vertebrate palaeontologist, our form is a very primitive 

 one in some respects, and a highly specialized one in other 

 respects, belonging to the early types of Mastodon. The primitive 

 characters of the fossil, he says, lie in the presence of successional 

 incisors, while its highly specialized and aberrant characters lie 

 in the peculiar form and arrangement of the mammilate cusps 

 of the molars, and the narrow, compressed or connate roots 

 supporting them. 



The following is a detailed description of our new form. 



SKULL. 



T'he specimen is a very well preserved skull, whose hind 

 portion, however, is broken away (PI. I & 11). It is small, compared 

 with the skull of other Proboscidea, the length being considerably 

 greater than the breadth. The whole length of the skull is 55™' (1.8 

 ft.) ; from the anterior extremity of the upper jaw to the anterior 



