534 Dr. 0. I. Forsyth Major on the 



the tubercles of the second series from without — the '' para- 

 cone" and "metacone " — are found to be in close juxtaposition; 

 the talon has diminished in size, but nevertheless attains to 

 about two thirds of the height of the " paracone." Inter- 

 mediate tubercles as such are not present ; on the other hand, 

 from both sides of the talon, in the neighbourhood of which 

 they broaden out to a certain extent, two basal ridges run 

 towards the exterior along the anterior and posterior margin 

 of the tooth, the anterior one reaching the external margin, 

 while the posterior ends at about the middle of the tooth. 



Solenodon. — The " paracone " and " metacone " are fused 

 together, in consequence of which the molars have become 

 still narrower than in the foregoing genus. The talon, too, 

 has diminished still further in height and extent. The poste- 

 rior basal margin ends on the inside, in line with the talon, in 

 a more feebly developed tubercle, the homologue of the 

 " metaconule " of Myogale. 



In Centetidce the " paracone " and " metacone " likewise 

 appear to be fused together. That it actually is a case of 

 fusion, i. e. tliat the main cusp of the molars is not to be 

 regarded as homologous with the " paracone " alone, is shown, 

 on the one hand, by the state of things in Potamogale, in 

 which the molars in this and other respects occupy an inter- 

 mediate position between those of Insectivora with " para- 

 cone " and " metacone " widely separated one from another 

 and those with an unpaired main cusp (Solenodontid^e, 

 Chrysochlorida^, Centetida), and, on the other, by the con- 

 dition seen in Oryzoryctes. In the intact M. 1 of this genus, 

 as also in the intact P.d. 1 — in the case of 0. liova more 

 distinctly than in that of 0. tetradactylas and 0. niger — the 

 " paracone " appears bicuspid ; the posterior cusp is much 

 less developed than the anterior, and, as in the case of Pota- 

 mogale, is shifted somewhat further than the latter, towards 

 the outside. In Oryzoryctes this metacone occurs besides 

 in P.d. 2 (Hens.) and P.d. 3 (Hens.), and is seen with great 

 distinctness in their successors P. 2 and P. 3. In the case of 

 Microgale I find that it is present neither in the molars nor 

 in the premolars, with the sole exception of P.d. 2 (Hens.). 



The talon (" protocone ") in Ceutetid^ is reduced still 

 further than in Solenodoi, until it entirely disappears 

 {Ceidetes) ; on the other hand, in the latter genus the anterior 

 and posterior basal ridges on both sides of the internal base 

 of the united para- and metacone swell up in the shape of 

 cusps, the posterior to a greater degree than the anterior; 

 the former appears as an independent cusp on P. 1 and P. 2. 



