Teeth in the Ccntetidse. 543 



/. 1. In connexion with tliis process C. exhibits all grada- 

 tions from the tjpical clevolopmcnt clown to complete agree- 

 ment with the surrounding incisors or premolars." In his 

 subsequent paper the author in question states that Echinops 

 is the only member of the Centctida3 that has taken this 

 direction. 



A somewhat similar state of things is found among 

 Centetidaj also in the case of Microgale Dohsoni and 

 Limnogale. Besides, in the various genera that here come 

 under consideration we are confronted with slightly different 

 ))rocesses, which must be kept distinct. A comminceni'int in 

 the direction of Echinops is already perceptible in the case 

 of Ericulits, since the upper /. 1 and the lower /. 2 have 

 increased in strength, although they do not, as in Echinops^ 

 surpass the corresponding C. In both genera /. 1 inf. has 

 been but little aflected, though the upper and lower /. 3 (and 

 /,(/. 3 previously) have sutfered all the more and have been 

 completely supjjresscd. The case is much the same with 

 regard to M. Dohsoni. It is true that here we still have three 

 incisors above and below, but the lower /. 3 is a very incon- 

 spicuous tooth, which in old individuals may be wanting on 

 one or both sides. The upper /. 1 and the lower /. 2 are very 

 powerful ; the former is longer than C, as in Echinops, but 

 /. 2 inf. also overtops considerably the lower C, while in 

 Echinops both teeth are of equal strength, and in Ericidus 0. 

 is the larger. — In Limnogale the conditions are somewhat 

 difterent. Here also the lower /. 2, like the upper /. 1, have 

 been more powerfully developed than C. ; but in the upper 

 jaw the two posterior /., the canine, and the anterior premolar 

 have all become practically ecp.iivalent in size and form, have 

 assumed almost the shape of canines, with recurved tips. The 

 corresponding milk-teeth of Limnogale differ to no very great 

 extent from the permanent ones, but are somewhat more 

 dissimilar in themselves. The same statement applies to the 

 lower /. 3, C, and P. 3. The latter, which otherwise through- 

 out the Centetidffi, with the exception of M. pusilla and now 

 and then of Echinops, has two roots, in Limnogale (I have 

 only one adult specimen before me) has a single root. Its 

 precursor in the milk-dentition possesses in one instance two 

 closely approximated roots j in a second example it, like P. 3, 

 is single-rooted. Even the middle lower premolar (P. 2, 

 Hens.) of Limnogale shows an approach to the form of the 

 antemolars in front of it, and, like its precursor P.d. 2, it is 

 without the internal cusp (" metaconid "). 



The analogy between Limnogale and Potamogale in the 

 condition of the antemolars is obvious. In both genera we 



