On the Teeth in the Ccntetidte. 525 



LXV. — On the Change and Form of the Teeth in the Centc- 

 tida;, a Malagasy Family of Insectivora. By C. I. 

 FOKSYTU MaJOU. 



Among the fruits of my two years' sojourn in Madagascar is 

 a rich series of recent Insectivora (Centetidse), and since a 

 considerable time must still ehipse before this is completely 

 worked out in a monograph *, 1 now give in a condensed 

 shape in the following pages the most essential facts as to 

 the change and form of the teeth in the family in question, 

 80 far as it has yet been possible to render the material avail- 

 able for examination. 



A. 



The Change of the Teeth. 



Oryzoryctes tetradactylus. 



Stage I. I.J. 1 and/.o?. 3 have come through almost completely; 

 of the remaining milk-teeth the tips alone protrude. The 

 C.d. are the most backward. 



Stage 11. All milk-teeth protrude from the jaws to their full 

 extent, with the exception of C.d.^ of which the posterior 

 basal cusp is not yet visible. M. 1 begins to protrude. 



Stage III. Skull somewhat shorter than in II. — All milk- 

 teeth are comj)letely protruded, with the exception of 

 C.d. inf.y of which the posterior basal cusp is not yet 

 visible. The greater portion of M. 1 is protruded 



Stage IV. All milk-teeth completely protruded, as also M, 1 ; 

 M. 2 partly so. 



Stage V. Like IV. ; but M. 2 is further advanced. Ld.Ssup. 

 dext. on the point of falling out. 



Stage VI. Skull somewhat longer than in VII. and VIIL— 

 M. 1 is m situ ; J/. 3 sup. and inf. on the point of coming 

 through. I.d. 1 and J.d. 3 suj). and inf. have been shed. 

 /. 3 sup. and inf. altogether t7i situ ; 1. 1 sup. not yet 

 completely so. 1. 1 inf. is more backward on the right 

 than on the left. P. 3 (Hens.) is commencing to raise 

 P.d. 3. 



Stage VII. Skull a shade longer than that of VIIL— .1/. 3 

 sup. is somewhat further advanced than in the latter, 

 M. 3 inf. somewhat more backward. In the change of 

 teeth VII. is somewhat less further advanced than VIII. 



* The diagnoses of most of the new species have already been pub- 

 lished. Cf. Ann. Mag. Nat. Hist. ser. 6, vol. xviii. 1896, pp. 318-322, 

 461-462. 



