NOTES ON A NKW FOSSIL MAMMAL. "^ 



INCISORS. 



The teeth arc very characteristic in form. Incisors are all 

 tusk-shaped, ([uite h(jrizontalIy phiced and not curved at the tip. 

 There are found two paii's in the lower jaw and one pair in the upper, 

 (See PL I). The upper incisors liave not yet come into full growth, 

 only the left tooth beinu' slio-htly visible below the broken maxill-cê. 

 The two ])airs of incisors in the lower jaw, especially the inner pair or 

 Ij, are prolonged beyond the anterior extremity of the jaw bone. 

 Incisors are verv Ion"- and 7)robablv 20'"" or more in length when 

 measured from the extremity of the root to the summit of the crown. 

 Thev are entirely covered by a thick coating of enamel, with 

 the thick dentine and the pulp cavity inside. In the lower L, a 

 transverse section at the distance of 7.8"^'" from the summit has the 

 diameter of o.l5'^"', where the enamel is 1.5'""' thick, the dentine 6""" 

 and the diameter of the pulp cavity 1.65"" (fig. 1). Towards the 

 summit, the enamel becomes thicker measuring 3""" in thickness, 

 while tlie dentine has the diameter of l.-l"'" with no pulp cavity at 

 the distance of o.2'"' from the summit (fig. 2). The upper jaw seems 

 to have only one pair of incisors, for the transverse section of the 

 skull at tlie distance of a1)out 22'"" from the anterior extremity shows 

 no trace of teeth (fig. 4). 



PREPyiOLARS AND MOLARS. 



Behind the incisc^rs there is a wide gap in both jaws. The teeth 

 collected by us are the right lower PMi, the right upper PM,, the 

 right and left lower PM.,, the left lower M, and the right and left upper 

 M. They all possess very |)eculiar forms never found in Proboscidea, 

 or even in other Mammalia. The crown is an aggregation of long 

 cylindrical column-like tubercles, which are generally arranged in two 

 longitudinal rows, parallel to tlie longer axis of the crown, and in 



