526 Dr. C. I. Forsyth Major on the 



Upper jaw : I.d. 3 has been shed and its successor is 

 in Situ ; I.d. 1 has likewise disappeared, /. 1 not yet com- 

 pletely in situ ; I.d. 2 still present on both sides. P.d. 3 

 still rests like a cap upon its successor. Lower jaw: 

 I.d. 1 has been shed, but its successor has not yet come 

 through completely. Ld, 3 has likewise been shed, and 

 its successor is in situ ; I.d. 2 is still present. P.d. 3 

 has been shed, P. 3 is not yet completely protruded. C.d., 

 P.d. 2, and P.d. 1 are still in place above and below. 

 M. 3 sup. and inf. are nearly in situ and already partly 

 in use. 



Stage VIII. M. 3 almost protruded above, entirely so below. 

 Upper jaw : The change of the anterior and posterior 

 pairs of Z. has been consummated, and the permanent 

 teeth are in situ. Id. 2 is still present on the left side ; 

 on the right it has been shed, and I. 2 is beginning to 

 appear. In the lower jaw the change of the anterior 

 and posterior pairs has likewise taken place, and /. 1 

 and /. 3 are in situ ; I.d. 2 is still present on both sides, 

 as are also all four C.d. P.d. 3 has disappeared above 

 and below, and the P. 3 are almost completely in place. 

 The posterior milk-premolars {P.d. 1 and P.d. 2) are 

 still present. 



Stage IX. But little further advanced than VIII.— J/. 3 

 sup. is in situ as well as M. 3 inf. Tlie only other 

 difference from VIII. consists in tlie fact that I.d. 2 has 

 been shed on both sides ; /. 2 is not yet in situ. The 

 tip of C. sup. is visible, in front of C.d. ; C. inf. is coming 

 into view on the inside of C.d. 



Stage X. The change of the whole of the teeth is accom- 

 plished. C. is not yet completely in situ, and is con- 

 sequently the last tooth to be replaced, as also its 

 precursor is the last to appear in the milk-dentition. 



Oryzoryctes hova. 



Stage I. All milk-teeth in situ. M. 1 is almost entirely 

 exposed ; M. 2 is beginning to protrude. 



Stage II. Milk-teeth as in I. M. 1 and M. 2 somewhat 

 further advanced, M. 1 inf. completely in situ. 



Stage III. I.d. 1 and I.d. 3 have been replaced above and 

 below ; I.d. 2 and likewise C.d. are still in situ. P.d. 3 

 sup. has been shed on the right, on the left it still rests 

 like a cap upon P. 3, which is coming into position. 

 P.d. 1 and P.d. 2 sup. and inf. are still in situ. All 

 three molars are completely developed and in situ. 



