82 ARKIV FÖR ZOOLOGI. BAND 14. N:0 4. 



as figured by Mjöberg^ is also very similar to the same of 

 Caenolestes. In some other Marsupials like Marmosa, Meta- 

 chirus, Dasyurus etc. several of the palatal ridges also in 

 the middle of the series, or even the majority, except the 

 hindmost ones, are more or less convex in a forward direc- 

 tion, thiis not straight träns verse, but otherwise the general 

 arrangement is rather similar. It is therefore probable that 

 this is the primitive pattern for the palatal ridges among 

 mammals. This is the more probable as a more or less 

 similar pattern also is to be seen in members of some other 

 orders as Insectivora (f. i. Erinaceus) and Carnivora (f. i. 

 Vnlpes, Canis, Otocyon etc.) as well. But when the mouth 

 is specialised in one direction or the other the palatal pattern 

 is changed. So has f. i. Perameles with its lengthened snout 

 got an increased number of curved palatal ridges in the 

 anterior part of the mouth. 



The tongue of Caenolestes is in accordance with the 

 mouth cavity, which it entirely fills, long. It is strongly 

 developed and fleshy. Its upper surface is densely beset 

 with filiform papillae so that it looks almost velvety. The 

 papillae fungiformes are in a considerable number distri- 

 buted över the upper surface, especially on either side 

 of the median line on the back of the tongue. But they are 

 also very numerous on the tip of the organ, where several 

 sit so close to the lateral margin that they strongly project 

 beyond the same and give it an uneven, almost fringed appe- 

 arance. A similar arrangement of papillae fungiformes is also 

 to be seen at the tip of the tongue of Marmosa, Metachirus 

 and Didelphys but also in Diprotodonts like Eudromicia. On 

 the base of the tongue sit three papillae vallatae arranged in 

 a triangle with the base forwards as usual. 



Not quite so far back and extending further forward 

 there are on either side of the base of the tongue very 

 strongly developed papillae foliatae. 



The lower side of the tongue is strongly keeled mesially, 

 and this keel is produced in front to a tip, which projects 

 beyond the anterior end of the tongue itself. This tip fits 

 in very well in the interspace between the two long anterior 

 incisors and may be used for cleaning this interspace from 



* K. Vet. Akad. Handl. Bd 52, n:o 2. Stockholm 1916, p. 16. 



